SEC Form S-3 filed by Nano Nuclear Energy Inc.

As filed with the Securities and Exchange Commission on July 25, 2025

Registration No. 333-[●]

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-3

REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

NANO NUCLEAR ENERGY INC.

(Exact name of registrant as specified in its charter)

10 Times Square, 30^th Floor

New York, NY 10018
Telephone: (212) 634-9206

(Address, including zip code, and telephone number, including area code, of registrant’s principal executive offices)

James Walker

Chief Executive Officer

Nano Nuclear Energy Inc.

10 Times Square, 30^th Floor

New York, NY 10018
Telephone: (212) 634-9206 

(Name, address, including zip code, and telephone number, including area code, of agent for service)

Please send a copy of all communications to:

Richard I. Anslow, Esq.

Lawrence A. Rosenbloom, Esq.

Ellenoff Grossman & Schole LLP

1345 Avenue of the Americas

New York, NY 10105

Tel: (212) 370-1300

Approximate date of commencement proposed sale to the public: from time to time after the effective date of this Registration Statement.

If the only securities being registered on this Form are being offered pursuant to dividend or interest reinvestment plans, please check the following box. ☐

If any of the securities being registered on this Form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, other than securities offered only in connection with dividend or interest reinvestment plans, check the following box. ☒

If this Form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, please check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering. ☐

If this Form is a registration statement pursuant to General Instruction I.D. or a post-effective amendment thereto that shall become effective upon filing with the Commission pursuant to Rule 462(e) under the Securities Act, check the following box. ☐

If this Form is a post-effective amendment to a registration statement filed pursuant to General Instruction I.D. filed to register additional securities or additional classes of securities pursuant to Rule 413(b) under the Securities Act, check the following box. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” in Rule 12b-2 of the Exchange Act.:

The Registrant hereby amends this registration statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment that specifically states that this registration statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act, or until the registration statement shall become effective on such date as the Securities and Exchange Commission, acting pursuant to said Section 8(a), may determine.

EXPLANATORY NOTE

This registration statement contains two prospectuses:

The base prospectus immediately follows after this explanatory note. The specific terms of any securities to be offered pursuant to the base prospectus will be set forth in one or more prospectus supplements to the base prospectus.

The sales agreement prospectus for the $400,000,000 “at-the-market” offering program immediately follows after the base prospectus. The $400,000,000 of common stock that may be offered, issued and sold by us under the sales agreement prospectus is included in the $620,000,000 of securities that may be offered, issued and sold by us under the base prospectus. Upon termination of the sales agreement, any portion of the $400,000,000 included in the sales agreement prospectus that is not sold pursuant to the sales agreement prospectus will be available for sale in other offerings pursuant to the base prospectus and corresponding prospectus supplements, and if no shares are sold under the sales agreement prospectus, the full $620,000,000 of securities may be sold in other offerings pursuant to the base prospectus and any corresponding prospectus supplements.

The sales agreement prospectus includes the base prospectus, except that the sales agreement prospectus contains a different front and back cover page and sets forth additional information in the sections titled “About This Prospectus,” “The Offering,” “Risk Factors,” “Use of Proceeds,” “Dilution,” “Plan of Distribution” and “Legal Matters.”

The information contained in this preliminary prospectus is not complete and may be changed. No securities may be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities, and it is not soliciting an offer to buy these securities, in any jurisdiction where the offer or sale is not permitted.

$620,000,000

COMMON STOCK

PREFERRED STOCK

PURCHASE CONTRACTS

WARRANTS

SUBSCRIPTION RIGHTS

DEPOSITARY SHARES

DEBT SECURITIES

UNITS

We may offer and sell from time to time, in one or more series, any one of the following securities of Nano Nuclear Energy Inc. (the “Company,” “we,” “us” or “our”), for total gross proceeds of up to $620,000,000:

We may offer and sell these securities separately or together, in one or more series or classes and in amounts, at prices and on terms described in one or more offerings. We may offer securities through underwriting syndicates managed or co-managed by one or more underwriters or dealers, through agents, directly to purchasers or through a combination of these methods, on a continuous or delayed basis. If any underwriters, dealers or agents are involved in the sale of any securities with respect to which this prospectus is being delivered, the names of such underwriters, dealers or agents and any applicable fees, commissions, discounts or options to purchase additional shares to be provided to them will be set forth in a prospectus supplement. The prospectus supplement for each offering of securities will describe in detail the plan of distribution for that offering. The price to the public of such securities and the net proceeds we expect to receive from such a sale will also be set forth in the prospectus supplement. For general information about the distribution of securities offered, please see “Plan of Distribution” in this prospectus.

This prospectus describes the general terms of these securities and the general manner in which these securities will be offered. Each time our securities are offered, we will provide a prospectus supplement containing more specific information about the particular offering and attach it to this prospectus. The prospectus supplements may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectuses, as well as any documents incorporated by reference, before purchasing any of the securities being offered.

This prospectus may not be used to offer or sell securities without a prospectus supplement that includes a description of the method and terms of the offering.

Our common stock is listed on the Capital Market tier of The Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “NNE.” The last reported sale price of our common stock on July 22, 2025 was $34.25 per share. Prospective purchasers of our securities are urged to obtain current information as to the market prices of our securities, where applicable.

If we decide to seek a listing of any preferred stock, purchase contracts, warrants, subscriptions rights, depositary shares, debt securities or units offered by this prospectus, the related prospectus supplement will disclose the exchange or market on which the securities will be listed, if any, or where we have applied for listing, if anywhere.

An investment in the securities offered through this prospectus is speculative and involves a high degree of risk. You should carefully consider the risk factors beginning on page 15 of this prospectus and the risk factors in our most recent Annual Report on Form 10-K, which is incorporated by reference herein, as well as the risk factors in our other recently filed quarterly and current reports incorporated by reference herein, and in the relevant prospectus supplements. We urge you to carefully read this prospectus, the applicable prospectus supplements and any related free writing prospectuses, as well as any documents incorporated by reference in this prospectus or any prospectus amendments or supplements, before investing.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or passed upon the adequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is [●], 2025.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we have filed with the Securities and Exchange Commission, or SEC, employing a “shelf” registration process. Under this shelf registration process, we may offer and sell, either individually or in combination, in one or more offerings, any of the securities described in this prospectus, for total gross proceeds of up to $620,000,000. This prospectus provides you with a general description of the securities we may offer. Each time we offer securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize may also add, update or change any of the information contained in this prospectus or in the documents that we have incorporated by reference in this prospectus. This prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

We urge you to read carefully this prospectus, the applicable prospectus supplement and any related free writing prospectuses, as well as any documents incorporated by reference as described under the heading “Incorporation of Certain Information by Reference,” before investing in any of the securities being offered. You should rely only on the information contained in, or incorporated by reference in, this prospectus and any applicable prospectus supplement, along with the information contained in any related free writing prospectuses. We have not authorized anyone to provide you with different or additional information.

This prospectus is an offer to sell only the securities offered hereby, and only under circumstances and in jurisdictions where it is lawful to do so. The distribution of this prospectus and the offering of securities in certain jurisdictions may be restricted by law. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of securities and the distribution of this prospectus outside the United States.

The information appearing in this prospectus, any applicable prospectus supplement and any related free writing prospectuses is accurate only as of the date on the front of such document and any information we have incorporated by reference in this prospectus or any prospectus supplement is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or any related free writing prospectus, or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates. To the extent there are inconsistencies between any prospectus supplement, this prospectus and any documents incorporated by reference, the document with the most recent date will control.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.” The representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in the prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreement, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS

The information in this prospectus, any applicable prospectus supplement and any related free writing prospectuses, together with any information incorporated by reference in this prospectus and such prospectus supplement, contains “forward-looking statements” within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act. All statements other than statements of historical fact, including statements regarding our future operating results and financial position, our business strategy and plans, market growth, and our objectives for future operations, are forward-looking statements. These forward-looking statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

You can identify some of these forward-looking statements by words or phrases such as “may,” “will,” “could,” “would,” “expect,” “anticipate,” “aim,” “estimate,” “intend,” “plan,” “believe,” “is/are likely to,” “potential,” “project,” “target,” “continue” or the negative of these terms or other similar expressions, although not all forward-looking statements may contain these words. Forward-looking statements are only predictions and are based largely on our current expectations and projections about future events and financial trends that we reasonably believe may affect our business, financial condition and results of operations. Although we believe that the expectations reflected in our forward-looking statements are reasonable, actual outcomes could differ materially from those projected or assumed in any of our forward-looking statements. Our future business, financial condition and results of operations, as well as any forward-looking statements, are subject to change given the inherent risks and uncertainties of market and industry conditions.

Forward-looking statements are neither predictions nor guarantees of future outcomes. Forward-looking statements present estimates and assumptions only as of the date on the cover of the document in which they are contained, and are subject to significant known and unknown risks, uncertainties and assumptions. Accordingly, you are cautioned not to place undue reliance on forward-looking statements, which speak only as of the dates on which they are made. Important factors that could cause actual outcomes to differ materially from those in the forward-looking statements include, but are not limited to, those summarized below:

The foregoing does not represent an exhaustive list of matters that may be covered by the forward-looking statements contained herein or risk factors that we are faced with. Forward-looking statements necessarily involve risks and uncertainties, and our actual results could differ materially from those anticipated in the forward-looking statements due to a number of factors, including those set forth under “Risk Factors” and elsewhere contained or incorporated by reference in this prospectus. All written and oral forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by the cautionary statements contained above and throughout this prospectus. Prior to investing in our common stock, you should read this prospectus, our filings incorporated by reference herein and the documents we have filed as exhibits to this registration statement of which this prospectus is a part completely and with the understanding that our actual future results may be materially different from what we currently expect.

Except as required by law, we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. 

INDUSTRY AND MARKET DATA

Unless otherwise indicated, data concerning economic conditions, our industry, our markets and our competitive position are based on a variety of sources, including information from third-party industry analysts, publications, surveys and forecasts and our own estimates and research. These data involve a number of assumptions, estimates and limitations. Industry publications, surveys and forecasts and other public information generally indicate or suggest that their information has been obtained from sources believed to be reliable. None of the third-party industry data used in this prospectus were prepared on our behalf. The industry in which we operate is subject to a high degree of uncertainty and risk due to a variety of factors, including those described in “Risk Factors”. These and other factors could cause results to differ materially from those expressed in these data.

TRADEMARKS

We own or have rights to trademarks or trade names that we use in connection with the operation of our businesses, our corporate names, logos and websites. We may make references to our trademarks and service marks, and to those belonging to other entities. Solely for convenience, trademarks and trade names referred to may appear without ® or ^™ or similar symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent possible under applicable law, our rights or the rights of the applicable licensor to these trademarks and trade names. We do not intend our use or display of other companies’ trade names, trademarks, or service marks to imply a relationship with, or an endorsement or sponsorship of us by, any other companies. All other trademarks and service marks are the property of their respective owners.

RISK FACTORS

Investing in our securities is speculative and involves a high degree of risk. Before deciding whether to invest in our securities, you should carefully consider the risk factors included in our 2024 Annual Report on Form 10-K, subsequent Quarterly Reports on Form 10-Q and those that may be included in the prospectus, together with any applicable prospectus supplements and any related free writing prospectuses, as well as any documents incorporated by reference in this prospectus or such prospectus supplements. You should also carefully consider other information contained or incorporated by reference in this prospectus or any applicable prospectus supplements, including our financial statements and the related notes thereto incorporated by reference in this prospectus. The risks and uncertainties described in any applicable prospectus supplements and our other filings with the SEC incorporated by reference in this prospectus and such prospectus supplements are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently consider immaterial could also adversely affect us. If any of risks we describe occur, our business, financial condition or results of operations could be materially harmed. In such case, the value of our securities could decline and you may some or lose all of your investment. Please also carefully consider the section entitled “Cautionary Note Regarding Forward-Looking Statements.”

USE OF PROCEEDS

Unless otherwise indicated in the applicable prospectus supplement, we intend to use the net proceeds from these sales for the advancement and development of our technologies, general working capital and general corporate purposes, which may include investing in or acquiring synergistic or complementary businesses, assets or technologies, and working capital, although as of the date of this prospectus, we have not entered into any definitive agreements. The amounts and timing of these expenditures will depend on numerous factors, including the development of our current business initiatives. Our management will have broad discretion to allocate the net proceeds, if any, we receive in connection with securities offered pursuant to this prospectus for any purpose.    Pending use of the net proceeds, we intend to invest the net proceeds in short-term, interest-bearing, investment-grade securities or in cash or money market funds.

DIVIDEND POLICY

We have never declared or paid any cash dividends on our capital stock, and we do not anticipate paying any cash dividends in the foreseeable future. The payment of dividends, if any, in the future is within the discretion of our board of directors and will depend on our earnings, capital requirements and financial condition and other relevant facts. We currently intend to retain all future earnings, if any, to finance the development and growth of our business.

DESCRIPTION OF SECURITIES WE MAY OFFER

General

This prospectus describes the general terms of our securities. The following description is not complete and may not contain all the information you should consider before investing in our securities. For a more detailed description of these securities, you should read the applicable provisions of Nevada law and our amended articles of incorporation, referred to herein as our charter, and our amended and restated bylaws, referred to herein as our bylaws. When we offer to sell a particular series of these securities, we will describe the specific terms of the series in a supplement to this prospectus. Accordingly, for a description of the terms of any series of securities, you must refer to both the prospectus supplement relating to that series and the description of the securities described in this prospectus. To the extent the information contained in the prospectus supplement differs from this summary description, you should rely on the information in the prospectus supplement.

Our authorized capital stock consists of 300,000,000 shares, par value $0.0001 per share, consisting of: 275,000,000 shares of common stock and 25,000,000 shares of preferred stock, all of which are currently undesignated. Our authorized but unissued shares of common stock and preferred stock are available for issuance without further action by our stockholders, unless such action is required by applicable law or the rules of any stock exchange or automated quotation system on which our securities may be listed or traded in the future.

We, directly or through agents, dealers or underwriters designated from time to time, may offer, issue and sell, together or separately, up to $620,000,000 in the aggregate of:

We may issue the debt securities exchangeable for or convertible into shares of common stock, preferred stock or other securities that may be sold by us pursuant to this prospectus, or any combination of the foregoing. The preferred stock may also be exchangeable for or convertible into shares of common stock, another series of preferred stock or other securities that may be sold by us pursuant to this prospectus, or any combination of the foregoing. When a particular series of securities is offered, a supplement to this prospectus will be delivered with this prospectus, which will set forth the terms of the offering and sale of the offered securities.

Common Stock

As of July 22, 2025, there were 41,539,423 shares of common stock issued and outstanding. In addition, there were 3,286,254 shares of common stock issuable upon exercise of outstanding warrants, 3,814,000 shares of common stock issuable upon exercise of outstanding stock options, and 350,748 shares of common stock issuable upon vesting of restricted stock units.

Our charter provides that each holder of common stock shall have the right to one (1) vote per share of common stock held of record by such holder as of the applicable record date on all matters submitted to a vote at any meeting of stockholders. The holders of outstanding shares of common stock are entitled to receive dividends out of assets or funds legally available for the payment of dividends of such times and in such amounts as our board of directors from time to time may determine. Our common stock is not entitled to pre-emptive rights and is not subject to redemption. Upon liquidation, dissolution or winding up of our company, the assets legally available for distribution to stockholders are distributable ratably among the holders of our common stock after payment of liquidation preferences, if any, on any outstanding payment of other claims of creditors. The rights, preferences and privileges of holders of common stock are subject to and may be adversely affected by the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. Our common stock is listed on Nasdaq under the trading symbol “NNE.” The transfer agent and registrar for our common stock is VStock Transfer, LLC, 18 Lafayette Place, Woodmere, NY 11598.

Preferred Stock

As of July 22, 2025, we had zero shares of preferred stock designated. Pursuant to our charter, our undesignated shares of preferred stock are “blank check” preferred stock, which means that our board of directors are authorized, without further action by the stockholders, to establish one or more class or series, and fix the relative rights and preferences of our undesignated preferred stock.

In connection with any offering of undesignated preferred stock, we will fix the rights, preferences, privileges and restrictions of the preferred stock of each series in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, the form of any certificate of designation that describes the terms of the series of preferred stock we are offering before the issuance of the related series of preferred stock. This description will include any or all of the following, as required:

If we offer shares of preferred stock under this prospectus, after receipt of payment therefor, the shares will be fully paid and non-assessable.

Nevada corporation law provides that the holders of preferred stock will have the right to vote separately as a class on any proposal involving fundamental changes in the rights of holders of that preferred stock. This right is in addition to any voting rights provided for in the applicable certificate of designation.

Our board of directors may authorize the issuance of preferred stock with voting or conversion rights that could adversely affect the voting power or other rights of the holders of our common stock. Preferred stock could be issued quickly with terms designed to delay or prevent a change in control of our Company or make removal of management more difficult. Additionally, the issuance of preferred stock could have the effect of decreasing the market price of our common stock.

Purchase Contracts

We may issue purchase contracts, representing contracts obligating holders to purchase from us, and us to sell to the holders, a specific or varying number of common stock, preferred stock, warrants, subscription rights, depositary shares, debt securities, or any combination of the above, at a future date or dates. Alternatively, the purchase contracts may obligate us to purchase from holders, and obligate holders to sell to us, a specific or varying number of common stock, preferred stock, warrants, subscription rights, depositary shares, debt securities, or any combination of the above. The price of the securities and other property subject to the purchase contracts may be fixed at the time the purchase contracts are issued or may be determined by reference to a specific formula set forth in the purchase contracts. The purchase contracts may be issued separately or as a part of a unit that consists of (a) a purchase contract and (b) one or more of the other securities that may be sold by us pursuant to this prospectus or any combination of the foregoing, which may secure the holders’ obligations to purchase the securities under the purchase contract. The purchase contracts may require us to make periodic payments to the holders or require the holders to make periodic payments to us. These payments may be unsecured or prefunded and may be paid on a current or on a deferred basis. The purchase contracts may require holders to secure their obligations under the contracts in a manner specified in the applicable prospectus supplement.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, forms of the purchase contracts and purchase contract agreements, if any. The applicable prospectus supplement will describe the terms of any purchase contracts in respect of which this prospectus is being delivered, including, to the extent applicable, the following:

Warrants

We may issue warrants to purchase our securities or other rights, including rights to receive payment in cash or securities based on the value, rate or price of one or more specified commodities, currencies, securities or indices, or any combination of the foregoing. Warrants may be issued independently or together with any other securities that may be sold by us pursuant to this prospectus or any combination of the foregoing and may be attached to, or separate from, such securities. To the extent warrants that we issue are to be publicly traded, each series of such warrants will be issued under a separate warrant agreement to be entered into between us and a warrant agent.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, forms of the warrants and warrant agreements, if any. The prospectus supplement relating to any warrants that we may offer will contain the specific terms of the warrants and a description of the material provisions of the applicable warrant agreement, if any. These terms may include the following:

Each warrant will entitle the holder of warrants to purchase the amount of securities or other rights, at the exercise price stated or determinable in the prospectus supplement for the warrants. Warrants may be exercised at any time up to the close of business on the expiration date shown in the applicable prospectus supplement, unless otherwise specified in such prospectus supplement. After the close of business on the expiration date, if applicable, unexercised warrants will become void. Warrants may be exercised in the manner described in the applicable prospectus supplement. When the warrant holder makes the payment and properly completes and signs the warrant certificate at the corporate trust office of the warrant agent, if any, or any other office indicated in the prospectus supplement, we will, as soon as possible, forward the securities or other rights that the warrant holder has purchased. If the warrant holder exercises less than all of the warrants represented by the warrant certificate, we will issue a new warrant certificate for the remaining warrants.

Subscription Rights

We may issue rights to purchase our securities. The rights may or may not be transferable by the persons purchasing or receiving the rights. In connection with any rights offering, we may enter into a standby underwriting or other arrangement with one or more underwriters or other persons pursuant to which such underwriters or other persons would purchase any offered securities remaining unsubscribed for after such rights offering. In connection with a rights offering to holders of our securities, a prospectus supplement will be distributed to such holders on the record date set by us for receiving rights in the rights offering.

We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, forms of the subscription rights, standby underwriting agreements or other agreements, if any. The prospectus supplement relating to any rights that we offer will include specific terms relating to the offering, including, among other matters:

Each right would entitle the holder of the rights to purchase the principal amount of securities at the exercise price, if any, set forth in the applicable prospectus supplement. Rights may be exercised at any time up to the close of business on the expiration date for the rights provided in the applicable prospectus supplement. After the close of business on the expiration date, all unexercised rights will become void.

Holders may exercise rights as described in the applicable prospectus supplement. Upon receipt of payment, if any, and the rights certificate properly completed and duly executed at the corporate trust office of the rights agent, if any, or any other office indicated in the prospectus supplement, we will, as soon as practicable, forward the securities purchasable upon exercise of the rights. If less than all of the rights issued in any rights offering are exercised, we may offer any unsubscribed securities directly to persons other than stockholders, to or through agents, underwriters or dealers or through a combination of such methods, including pursuant to standby underwriting arrangements, as described in the applicable prospectus supplement.

Depositary Shares

General. We may offer fractional shares of preferred stock, rather than full shares of preferred stock. If we decide to offer fractional shares of preferred stock, we will issue receipts for depositary shares. Each depositary share will represent a fraction of a share of a particular series of our preferred stock, and the applicable prospectus supplement will indicate that fraction. The shares of preferred stock represented by depositary shares will be deposited under a deposit agreement between us and a depositary that is a bank or trust company that meets certain requirements and is selected by us. The depositary will be specified in the applicable prospectus supplement. Each owner of a depositary share will be entitled to all of the rights and preferences of the preferred stock represented by the depositary share. The depositary shares will be evidenced by depositary receipts issued pursuant to the deposit agreement. Depositary receipts will be distributed to those persons purchasing the fractional shares of our preferred stock in accordance with the terms of the offering. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, forms of the deposit agreements, forms of the certificates of designation of the underlying preferred stock, forms of depositary receipts and any other related agreements.

Dividends and Other Distributions. The depositary will distribute all cash dividends or other cash distributions received by it in respect of the preferred stock to the record holders of depositary shares relating to such preferred shares in proportion to the numbers of depositary shares held on the relevant record date.

In the event of a distribution other than in cash, the depositary will distribute securities or property received by it to the record holders of depositary shares in proportion to the numbers of depositary shares held on the relevant record date, unless the depositary determines that it is not feasible to make such distribution. In that case, the depositary may make the distribution by such method as it deems equitable and practicable. One such possible method is for the depositary to sell the securities or property and then distribute the net proceeds from the sale as provided in the case of a cash distribution.

Redemption of Depositary Shares. Whenever we redeem the preferred stock, the depositary will redeem a number of depositary shares representing the same number of shares of preferred stock so redeemed. If fewer than all of the depositary shares are to be redeemed, the depositary shares to be redeemed will be selected by lot, pro rata or by any other equitable method as the depositary may determine.

Voting of Underlying Shares. Upon receipt of notice of any meeting at which the holders of our preferred stock of any series are entitled to vote, the depositary will mail the information contained in the notice of the meeting to the record holders of the depositary shares relating to that series of preferred stock. Each record holder of the depositary shares on the record date will be entitled to instruct the depositary as to the exercise of the voting rights represented by the number of shares of preferred stock underlying the holder’s depositary shares. The depositary will endeavor, to the extent it is practical to do so, to vote the number of whole shares of preferred stock underlying such depositary shares in accordance with such instructions. We will agree to take all action that the depositary may deem reasonably necessary in order to enable the depositary to do so. To the extent the depositary does not receive specific instructions from the holders of depositary shares relating to such preferred shares, it will abstain from voting such shares of preferred stock.

Withdrawal of Shares. Upon surrender of depositary receipts representing any number of whole shares at the depositary’s office, unless the related depositary shares previously have been called for redemption, the holder of the depositary shares evidenced by the depositary receipts will be entitled to delivery of the number of whole shares of the related series of preferred stock and all money and other property, if any, underlying such depositary shares. However, once such an exchange is made, the preferred stock cannot thereafter be re-deposited in exchange for depositary shares. Holders of depositary shares will be entitled to receive whole shares of the related series of preferred stock on the basis set forth in the applicable prospectus supplement. If the depositary receipts delivered by the holder evidence a number of depositary shares representing more than the number of whole shares of preferred stock of the related series to be withdrawn, the depositary will deliver to the holder at the same time a new depositary receipt evidencing the excess number of depositary shares.

Amendment and Termination of Depositary Agreement. The form of depositary receipt evidencing the depositary shares and any provision of the applicable depositary agreement may at any time be amended by agreement between us and the depositary. We may, with the consent of the depositary, amend the depositary agreement from time to time in any manner that we desire. However, if the amendment would materially and adversely alter the rights of the existing holders of depositary shares, the amendment would need to be approved by the holders of at least a majority of the depositary shares then outstanding.

The depositary agreement may be terminated by us or the depositary if:

Resignation and Removal of Depositary. The depositary may resign at any time by delivering to us notice of its election to do so. We may remove a depositary at any time. Any resignation or removal will take effect upon the appointment of a successor depositary and its acceptance of appointment.

Charges of Depositary. We will pay all transfer and other taxes and governmental charges arising solely from the existence of any depositary arrangements. We will pay all charges of each depositary in connection with the initial deposit of the preferred shares of any series, the initial issuance of the depositary shares, any redemption of such preferred shares and any withdrawals of such preferred shares by holders of depositary shares. Holders of depositary shares will be required to pay any other transfer taxes.

Notices. Each depositary will forward to the holders of the applicable depositary shares all notices, reports and communications from us which are delivered to such depositary and which we are required to furnish the holders of the preferred stock represented by such depositary shares.

Miscellaneous. The depositary agreement may contain provisions that limit our liability and the liability of the depositary to the holders of depositary shares. Both the depositary and we are also entitled to an indemnity from the holders of the depositary shares prior to bringing, or defending against, any legal proceeding. We or any depositary may rely upon written advice of counsel or accountants, or information provided by persons presenting preferred shares for deposit, holders of depositary shares or other persons believed by us to be competent and on documents believed by us or them to be genuine.

Debt Securities

As used in this prospectus, the term “debt securities” means the debentures, notes, bonds and other evidences of indebtedness that we may issue from time to time. The debt securities will be either senior debt securities, senior subordinated debt securities or subordinated debt securities. We may also issue convertible debt securities. Debt securities may be issued under an indenture, which is a contract entered into between us and a trustee to be named therein. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report on Form 8-K that we file with the SEC, the indentures or other agreements, if any. We may issue debt securities and incur indebtedness other than through the offering of debt securities pursuant to this prospectus. Convertible debt securities may not be issued under an indenture.

The debt securities may be fully and unconditionally guaranteed on a secured or unsecured senior or subordinated basis by one or more guarantors, if any. The obligations of any guarantor under its guarantee will be limited as necessary to prevent that guarantee from constituting a fraudulent conveyance under applicable law. In the event that any series of debt securities will be subordinated to other indebtedness that we have outstanding or may incur, the terms of the subordination will be set forth in the prospectus supplement relating to the subordinated debt securities.

We may issue debt securities from time to time in one or more series, in each case with the same or various maturities, at par or at a discount. Unless indicated in a prospectus supplement, we may issue additional debt securities of a particular series without the consent of the holders of the debt securities of such series outstanding at the time of the issuance. Any such additional debt securities, together with all other outstanding debt securities of that series, will constitute a single series of debt securities under the applicable indenture and will be equal in ranking.

Should an indenture relate to unsecured indebtedness, in the event of a bankruptcy or other liquidation event involving a distribution of assets to satisfy our outstanding indebtedness or an event of default under a loan agreement relating to secured indebtedness of our company or its subsidiaries, the holders of such secured indebtedness, if any, would be entitled to receive payment of principal and interest prior to payments on the unsecured indebtedness.

Each prospectus supplement will describe the terms relating to the specific series of debt securities. These terms will include some or all of the following:

Unless otherwise specified in the applicable prospectus supplement, we do not anticipate the debt securities will be listed on any securities exchange. Holders of the debt securities may present registered debt securities for exchange or transfer in the manner described in the applicable prospectus supplement. Except as limited by the applicable indenture, we will provide these services without charge, other than any tax or other governmental charge payable in connection with the exchange or transfer.

Debt securities may bear interest at a fixed rate or a variable rate as specified in the prospectus supplement. In addition, if specified in the prospectus supplement, we may sell debt securities bearing no interest or interest at a rate that at the time of issuance is below the prevailing market rate, or at a discount below their stated principal amount. We will describe in the applicable prospectus supplement any special federal income tax considerations applicable to these discounted debt securities.

We may issue debt securities with the principal amount payable on any principal payment date, or the amount of interest payable on any interest payment date, to be determined by referring to one or more currency exchange rates, commodity prices, equity indices or other factors. Holders of such debt securities may receive a principal amount on any principal payment date, or interest payments on any interest payment date, that are greater or less than the amount of principal or interest otherwise payable on such dates, depending upon the value on such dates of applicable currency, commodity, equity index or other factors. The applicable prospectus supplement will contain information as to how we will determine the amount of principal or interest payable on any date, as well as the currencies, commodities, equity indices or other factors to which the amount payable on that date relates and certain additional tax considerations.

Units

We may issue units consisting of any combination of the other types of securities offered under this prospectus in one or more series. We may evidence each series of units by unit certificates that we may issue under a separate agreement. We may enter into unit agreements with a unit agent. Each unit agent, if any, may be a bank or trust company that we select. We will indicate the name and address of the unit agent, if any, in the applicable prospectus supplement relating to a particular series of units. Specific unit agreements, if any, will contain additional important terms and provisions. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from a current report that we file with the SEC, the form of unit and the form of each unit agreement, if any, relating to units offered under this prospectus.

If we offer any units, certain terms of that series of units will be described in the applicable prospectus supplement, including, without limitation, the following, as applicable:

FORMS OF SECURITIES

Each security may be represented either by a certificate issued in definitive form to a particular investor or by one or more global securities representing the entire issuance of securities. Certificated securities in definitive form and global securities will be issued in registered form. Definitive securities name you or your nominee as the owner of the security, and in order to transfer or exchange these securities or to receive payments other than interest or other interim payments, you or your nominee must physically deliver the securities to the trustee, registrar, paying agent or other agent, as applicable. Global securities name a depositary or its nominee as the owner of the debt securities, warrants or units represented by these global securities. The depositary maintains a computerized system that will reflect each investor’s beneficial ownership of the securities through an account maintained by the investor with its broker-dealer, bank, trust company or other representative, as we explain more fully below.

Registered Global Securities

We may issue the securities in the form of one or more fully registered global securities that will be deposited with a depositary or its nominee identified in the applicable prospectus supplement and registered in the name of that depositary or nominee. In those cases, one or more registered global securities will be issued in a denomination or aggregate denominations equal to the portion of the aggregate principal or face amount of the securities to be represented by registered global securities. Unless and until it is exchanged in whole for securities in definitive registered form, a registered global security may not be transferred except as a whole by and among the depositary for the registered global security, the nominees of the depositary or any successors of the depositary or those nominees.

The specific terms of the depositary arrangement with respect to any securities to be represented by a registered global security will be described in the prospectus supplement relating to those securities. We anticipate that the following provisions will apply to all depositary arrangements.

Ownership of beneficial interests in a registered global security will be limited to persons, called participants, that have accounts with the depositary or persons that may hold interests through participants. Upon the issuance of a registered global security, the depositary will credit, on its book-entry registration and transfer system, the participants’ accounts with the respective principal or face amounts of the securities beneficially owned by the participants. Any dealers, underwriters or agents participating in the distribution of the securities will designate the accounts to be credited. Ownership of beneficial interests in a registered global security will be shown on, and the transfer of ownership interests will be effected only through, records maintained by the depositary, with respect to interests of participants, and on the records of participants, with respect to interests of persons holding through participants. The laws of some states may require that some purchasers of securities take physical delivery of these securities in definitive form. These laws may impair your ability to own, transfer or pledge beneficial interests in registered global securities.

So long as the depositary, or its nominee, is the registered owner of a registered global security, that depositary or its nominee, as the case may be, will be considered the sole owner or holder of the securities represented by the registered global security for all purposes under the applicable indenture, warrant agreement or unit agreement.

Except as described below, owners of beneficial interests in a registered global security will not be entitled to have the securities represented by the registered global security registered in their names, will not receive or be entitled to receive physical delivery of the securities in definitive form and will not be considered the owners or holders of the securities under the applicable indenture, warrant agreement or unit agreement. Accordingly, each person owning a beneficial interest in a registered global security must rely on the procedures of the depositary for that registered global security and, if that person is not a participant, on the procedures of the participant through which the person owns its interest, to exercise any rights of a holder under the applicable indenture, warrant agreement or unit agreement. We understand that under existing industry practices, if we request any action of holders or if an owner of a beneficial interest in a registered global security desires to give or take any action that a holder is entitled to give or take under the applicable indenture, warrant agreement or unit agreement, the depositary for the registered global security would authorize the participants holding the relevant beneficial interests to give or take that action, and the participants would authorize beneficial owners owning through them to give or take that action or would otherwise act upon the instructions of beneficial owners holding through them.

Payments to holders with respect to securities represented by a registered global security registered in the name of a depositary or its nominee will be made to the depositary or its nominee, as the case may be, as the registered owner of the registered global security. None of the Company, the trustees, the warrant agents, the unit agents or any other agent of the Company, agent of the trustees, the warrant agents or unit agents will have any responsibility or liability for any aspect of the records relating to payments made on account of beneficial ownership interests in the registered global security or for maintaining, supervising or reviewing any records relating to those beneficial ownership interests.

We expect that the depositary for any of the securities represented by a registered global security, upon receipt of any payment of principal, premium, interest or other payment or distribution to holders of that registered global security, will immediately credit participants’ accounts in amounts proportionate to their respective beneficial interests in that registered global security as shown on the records of the depositary. We also expect that payments by participants to owners of beneficial interests in a registered global security held through participants will be governed by standing customer instructions and customary practices, as is now the case with the securities held for the accounts of customers or registered in “street name,” and will be the responsibility of those participants.

If the depositary for any of these securities represented by a registered global security is at any time unwilling or unable to continue as depositary or ceases to be a clearing agency registered under the Exchange Act and a successor depositary registered as a clearing agency under the Exchange Act is not appointed by us within 90 days, we will issue securities in definitive form in exchange for the registered global security that had been held by the depositary. Any securities issued in definitive form in exchange for a registered global security will be registered in the name or names that the depositary gives to the relevant trustee, warrant agent, unit agent or other relevant agent of ours or theirs. It is expected that the depositary’s instructions will be based upon directions received by the depositary from participants with respect to ownership of beneficial interests in the registered global security that had been held by the depositary.

PLAN OF DISTRIBUTION

We may sell the securities from time to time to or through underwriters or dealers, through agents or directly to one or more purchasers. A distribution of the securities offered by this prospectus may also be effected through the issuance of derivative securities, including without limitation warrants, subscription rights or depositary shares. In addition, the manner in which we may sell some or all of the securities covered by this prospectus includes, without limitation, through:

A prospectus supplement or supplements with respect to each series of securities will describe the terms of the offering, including, to the extent applicable:

The offer and sale of the securities described in this prospectus by us, the underwriters or the third parties described above may be effected from time to time in one or more transactions, including privately negotiated transactions, either:

Only underwriters named in a prospectus supplement will be underwriters of the securities offered by such prospectus supplement.

Underwriters and Agents; Direct Sales

If underwriters are used in a sale, they will acquire the offered securities for their own account and may resell the offered securities from time to time in one or more transactions, including negotiated transactions, at a fixed public offering price or at varying prices determined at the time of sale. We may offer the securities to the public through underwriting syndicates represented by managing underwriters or by underwriters without a syndicate.

Unless the prospectus supplement states otherwise, the obligations of the underwriters to purchase the securities will be subject to the conditions set forth in the applicable underwriting agreement. Subject to certain conditions, the underwriters will be obligated to purchase all of the securities offered by the prospectus supplement, other than securities covered by any over-allotment option. Any public offering price and any discounts or concessions allowed or re-allowed or paid to dealers may change from time to time. We may use underwriters with whom we have a material relationship. We will describe in the prospectus supplement, naming the underwriter, the nature of any such relationship.

We may sell securities directly or through agents we designate from time to time. We will name any agent involved in the offering and sale of securities, and we will describe any commissions we will pay the agent in the prospectus supplement. Unless the prospectus supplement states otherwise, any agent will act on a best-efforts basis for the period of its appointment.

Dealers

We may sell the offered securities to dealers as principals. The dealer may then resell such securities to the public either at varying prices to be determined by the dealer or at a fixed offering price agreed to with us at the time of resale.

Institutional Purchasers

We may authorize agents, dealers or underwriters to solicit certain institutional investors to purchase offered securities on a delayed delivery basis pursuant to delayed delivery contracts providing for payment and delivery on a specified future date. The applicable prospectus supplement or other offering materials, as the case may be, will provide the details of any such arrangement, including the offering price and commissions payable for the solicitations.

We will enter into such delayed contracts only with institutional purchasers that we approve. These institutions may include commercial and savings banks, insurance companies, pension funds, investment companies and educational and charitable institutions.

Indemnification; Other Relationships

We may provide agents, underwriters, dealers and remarketing firms with indemnification against certain civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents or underwriters may make with respect to these liabilities. Agents, underwriters, dealers and remarketing firms, and their affiliates, may engage in transactions with, or perform services for, us in the ordinary course of business. These may include commercial banking and investment banking transactions, among other services.

Market-Making; Stabilization and Other Transactions

There is currently no market for any of the offered securities, other than our common stock, which is quoted on Nasdaq. If the offered securities are traded after their initial issuance, they may trade at a discount from their initial offering price, depending upon prevailing interest rates, the market for similar securities and other factors. While it is possible that an underwriter could inform us that it intends to make a market in the offered securities, such underwriter would not be obligated to do so, and any such market-making could be discontinued at any time without notice. Therefore, no assurance can be given as to whether an active trading market will develop for the offered securities. We have no current plans for listing of any debt securities, preferred stock, warrants or subscription rights on any securities exchange or quotation system; any such listing with respect to any particular debt securities, preferred stock, warrants or subscription rights will be described in the applicable prospectus supplement or other offering materials, as the case may be.

Any underwriter may engage in over-allotment, stabilizing transactions, syndicate-covering or other short-covering transactions and penalty bids in accordance with Regulation M under the Securities Exchange Act of 1934, as amended, or the Exchange Act. Over-allotment involves sales in excess of the offering size, which create a short position. Stabilizing transactions permit bids to purchase the underlying security so long as the stabilizing bids do not exceed a specified maximum price. Syndicate-covering or other short-covering transactions involve purchases of the securities, either through exercise of the over-allotment option or in the open market after the distribution is completed, to cover short positions. Penalty bids permit the underwriters to reclaim a selling concession from a dealer when the securities originally sold by the dealer are purchased in a stabilizing or covering transaction to cover short positions. Those activities may cause the price of the securities to be higher than it would otherwise be. If commenced, the underwriters may discontinue any of these activities at any time.

Any underwriters or agents that are qualified market makers on Nasdaq may engage in passive market making transactions in our common stock on Nasdaq in accordance with Regulation M under the Exchange Act, during the business day prior to the pricing of the offering, before the commencement of offers or sales of our common stock. Passive market makers must comply with applicable volume and price limitations and must be identified as passive market makers. In general, a passive market maker must display its bid at a price not in excess of the highest independent bid for such security; if all independent bids are lowered below the passive market maker’s bid, however, the passive market maker’s bid must then be lowered when certain purchase limits are exceeded. Passive market making may stabilize the market price of the securities at a level above that which might otherwise prevail in the open market and, if commenced, may be discontinued at any time.

Fees and Commissions

If 5% or more of the net proceeds of any offering of securities made under this prospectus will be received by a FINRA member participating in the offering or affiliates or associated persons of such FINRA member, the offering will be conducted in accordance with FINRA Rule 5121.

LEGAL MATTERS

Unless otherwise indicated in the applicable prospectus supplement, the validity of the securities offered by this prospectus will be passed upon for us by Parsons Behle & Latimer, Reno, Nevada. If legal matters in connection with offerings made by this prospectus are passed on by counsel for the underwriters, dealers or agents, if any, then such counsel will be named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Nano Nuclear Energy, Inc. and its consolidated subsidiaries, as of and for the fiscal years ended September 30, 2024 and 2023, incorporated in this prospectus by reference to our Annual Report on Form 10-K for the fiscal year ended September 30, 2024, have been so incorporated in reliance on the report of WithumSmith+Brown, PC, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

WHERE YOU CAN FIND MORE INFORMATION

This prospectus is part of the registration statement on Form S-3 that we have filed with the SEC under the Securities Act and does not contain all the information set forth or incorporated by reference in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement, or to the exhibits to the reports or other documents incorporated by reference in this prospectus, for a copy of such contract, agreement or other document. We file annual, quarterly and periodic reports, proxy statements and other information with the SEC, using its EDGAR system. The SEC provides free public access, through its website, to items publicly filed in the EDGAR system, including our items. The address of the SEC’s website is http//www.sec.gov.

We also maintain a website at www.nanonuclearenergy.com. You may access these materials at our website free of charge as soon as reasonably practicable after they are electronically filed with, or furnished to, the SEC. Information contained in, or that can be accessed through, our website is not a part of, and is not incorporated into, this prospectus.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE 

We are “incorporating by reference” in this prospectus certain documents we have filed or will file with the SEC, which means that we can disclose important information to you by referring you to those documents. The information incorporated by reference is considered to be part of this prospectus, and later information that we file with the SEC will automatically update and supersede this information. We incorporate by reference the documents listed below and any future filings made with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (1) after the date of the initial registration statement, as amended, and prior to effectiveness of the registration statement, and (2) after the date of this prospectus and prior to the termination of this offering, from their respective filing dates (other than any portions thereof, which under the Exchange Act, and applicable SEC rules, are not deemed “filed” under the Exchange Act). Such information will automatically update and supersede the information contained in this prospectus and the documents listed below:

1. Our Annual Report on Form 10-K for the fiscal year ended September 30, 2024, filed with the SEC on December 30, 2024 (the “2024 Annual Report”);

2. Our Quarterly Reports on Form 10-Q for the quarters ended December 31, 2024 and March 31, 2025, respectively, filed with the SEC on February 13, 2025 and May 15, 2025, respectively (the “Quarterly Reports”);

3. Our Definitive Proxy Statement filed with the SEC on February 28, 2025 and our Proxy Statement Supplement filed with the SEC on March 26, 2025;

4. Our Current Reports on Form 8-K filed with the SEC on October 18, 2024, October 25, 2024, October 30, 2024, November 27, 2024, December 26, 2024, January 14, 2025, March 12, 2025, April 24, 2025, May 29, 2025, June 5, 2025 and June 10, 2025, respectively (excluding any information therein disclosed under Items 2.02 or 7.01 or any corresponding information furnished under Item 9.01 or included as an exhibit); and

5. The description of our shares of common stock contained in the our registration statement on Form 8-A, filed with the SEC on May 6, 2024.

In addition, all documents and/or reports that we file with the SEC pursuant to Sections 13(a), 13(c), 14, and 15(d) of the Exchange Act subsequent to the date of the registration statement of which this prospectus is a part, and prior to the termination or completion of any applicable offering of securities under this prospectus or the filing of a post-effective amendment to such registration statement that indicates that all securities offered under this prospectus have been sold, or that deregisters all securities then remaining unsold, will be deemed to be incorporated herein by reference and to be a part hereof from the date of filing of such documents.

Notwithstanding the foregoing, none of the information that we disclose under Items 2.02 or 7.01 of any Current Report on Form 8-K, or any corresponding information furnished under Item 9.01 or included as an exhibit, that we may from time to time furnish to the SEC, will be incorporated by reference in, or otherwise included in, this prospectus, except as otherwise expressly set forth in the relevant document. Subject to the foregoing, all information appearing in this prospectus is qualified in its entirety by the information appearing in the documents incorporated by reference.

You may request, orally or in writing, a copy of the documents we incorporate by reference, which will be provided to you at no cost (other than exhibits, unless such exhibits are specifically incorporated by reference), by contacting our Secretary, c/o Nano Nuclear Energy Inc. at 10 Times Square, 30th Floor, New York, NY 10018. Our telephone number is (212) 634-9206.

$620,000,000

COMMON STOCK

PREFERRED STOCK

PURCHASE CONTRACTS

WARRANTS

SUBSCRIPTION RIGHTS

DEPOSITARY SHARES

DEBT SECURITIES

UNITS

PRELIMINARY PROSPECTUS

[●], 2025

The information contained in this preliminary prospectus is not complete and may be changed. No securities may be sold until the registration statement filed with the Securities and Exchange Commission is effective. This preliminary prospectus is not an offer to sell these securities, and it is not soliciting an offer to buy these securities, in any jurisdiction where the offer or sale is not permitted.

Up to $400,000,000 of Shares of Common Stock

Nano Nuclear Energy, Inc. (the “Company,” “we,” “us” or “our”) has entered into a sales agreement (the “Agreement”) with TD Securities (USA) LLC (“TD Cowen”), UBS Securities LLC and Piper Sandler & Co. (each a “Sales Agent” and together, the “Sales Agents”), relating to the sale of shares of our common stock, par value $0.0001 per share (our “common stock”), offered by this prospectus (including the base prospectus contained within the Registration Statement on Form S-3 of which this prospectus forms a part) (referred to herein as the “prospectus”). In accordance with the terms of the Agreement, we may offer and sell up to $400,000,000 of shares of our common stock from time to time through or to the Sales Agents acting as agents or principals.

Our common stock is listed on the Capital Market tier of The Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “NNE.” The last reported sale price of our common stock on July 22, 2025 was $34.25 per share.

Sales of our common stock, if any, under this prospectus may be made in negotiated transactions, including block trades, or transactions that are deemed to be “at the market” offerings as defined in Rule 415 under the Securities Act of 1933, as amended, or the Securities Act, including sales made by means of ordinary brokers’ transactions, including directly on Nasdaq, or sales made to or through a market maker other than on an exchange, at prevailing market prices, at prices related to prevailing market prices, at negotiated prices or by any other method permitted by law. The Sales Agents are not required to sell any specific dollar amount of shares but will use commercially reasonable efforts to sell on our behalf all of the shares requested to be sold by us, consistent with their normal trading and sales practices, on mutually agreed terms between us and the Sales Agents. There is no arrangement for funds to be received in any escrow, trust or similar arrangement. The Sales Agents may also purchase shares of our common stock as principals.

The compensation to the Sales Agents for sales of common stock sold pursuant to the Agreement will be an amount up to 3% of the gross proceeds of any shares of common stock sold under the Agreement. In connection with the sale of our common stock on our behalf, the Sales Agents may be deemed to be “underwriters” within the meaning of the Securities Act, and the compensation of the Sales Agents may be deemed to be underwriting discounts or commissions. See “Plan of Distribution” beginning on page S-22 for additional information regarding underwriting compensation. We have also agreed to provide indemnification and contribution to the Sales Agents with respect to certain liabilities, including liabilities under the Securities Act.

An investment in the securities offered through this prospectus is speculative and involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” beginning on page S-17 of this prospectus  and in the documents incorporated by reference in this prospectus.

Neither the Securities and Exchange Commission (“SEC”) nor any state securities commission has approved or disapproved of these securities or passed upon the accuracy or adequacy of this prospectus. Any representation to the contrary is a criminal offense.

The date of this prospectus is [●], 2025.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement on Form S-3 that we have filed with the Securities and Exchange Commission, or SEC, employing a “shelf” registration process Under this prospectus, we may offer and sell shares of our common stock having an aggregate offering price of up to $400,000,000 from time to time at prices and on terms to be determined by market conditions at the time of offering.

You should assume that the information contained in this prospectus and the documents incorporated by reference in this prospectus is accurate only as of the respective dates of those documents. To the extent there is a conflict between the information contained in this prospectus, on the one hand, and the information contained in any document incorporated by reference in this prospectus that was filed with the SEC before the date of this prospectus, on the other hand, you should rely on the information in this prospectus. If any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus that was filed with the SEC after the date of this prospectus — the statement in the document having the later date modifies or supersedes the earlier statement.

This prospectus contains summaries of certain provisions contained in some of the documents described herein, but reference is made to the actual documents for complete information. All of the summaries are qualified in their entirety by the actual documents. Copies of some of the documents referred to herein have been filed, will be filed or will be incorporated by reference as exhibits to the registration statement of which this prospectus is a part, and you may obtain copies of those documents as described below under the section entitled “Where You Can Find More Information” and “Incorporation of Certain Information by Reference.” The representations, warranties and covenants made by us in any agreement that is filed as an exhibit to any document that is incorporated by reference in the prospectus were made solely for the benefit of the parties to such agreement, including, in some cases, for the purpose of allocating risk among the parties to such agreement, and should not be deemed to be a representation, warranty or covenant to you. Moreover, such representations, warranties or covenants were accurate only as of the date when made. Accordingly, such representations, warranties and covenants should not be relied on as accurately representing the current state of our affairs.

We urge you to read carefully this prospectus, as well as any documents incorporated by reference as described under the heading “Incorporation of Certain Information by Reference,” before investing in any of the securities being offered. You should rely only on the information contained in, or incorporated by reference in, this prospectus. We have not, and the Sales Agents have not, authorized anyone to provide you with information that is in addition to or different from the information included or incorporated by reference in this prospectus.

CAUTIONARY NOTE REGARDING FORWARD LOOKING STATEMENTS

The information in this prospectus and any related free writing prospectuses, together with any information incorporated by reference in this prospectus, contains “forward-looking statements” within the meaning of Section 27A of the Securities Act, and Section 21E of the Exchange Act. All statements other than statements of historical fact, including statements regarding our future operating results and financial position, our business strategy and plans, market growth, and our objectives for future operations, are forward-looking statements. These forward-looking statements involve known and unknown risks, uncertainties and other important factors that may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements.

You can identify some of these forward-looking statements by words or phrases such as “may,” “will,” “could,” “would,” “expect,” “anticipate,” “aim,” “estimate,” “intend,” “plan,” “believe,” “is/are likely to,” “potential,” “project,” “target,” “continue” or the negative of these terms or other similar expressions, although not all forward-looking statements may contain these words. Forward-looking statements are only predictions and are based largely on our current expectations and projections about future events and financial trends that we reasonably believe may affect our business, financial condition and results of operations. Although we believe that the expectations reflected in our forward-looking statements are reasonable, actual outcomes could differ materially from those projected or assumed in any of our forward-looking statements. Our future business, financial condition and results of operations, as well as any forward-looking statements, are subject to change given the inherent risks and uncertainties of market and industry conditions.

Forward-looking statements are neither predictions nor guarantees of future outcomes. Forward-looking statements present estimates and assumptions only as of the date on the cover of the document in which they are contained, and are subject to significant known and unknown risks, uncertainties and assumptions. Accordingly, you are cautioned not to place undue reliance on forward-looking statements, which speak only as of the dates on which they are made. Important factors that could cause actual outcomes to differ materially from those in the forward-looking statements include, but are not limited to, those summarized below:

The foregoing does not represent an exhaustive list of matters that may be covered by the forward-looking statements contained herein or risk factors that we are faced with. Forward-looking statements necessarily involve risks and uncertainties, and our actual results could differ materially from those anticipated in the forward-looking statements due to a number of factors, including those set forth under “Risk Factors” and elsewhere contained or incorporated by reference in this prospectus. All written and oral forward-looking statements attributable to us or persons acting on our behalf are expressly qualified in their entirety by the cautionary statements contained above and throughout this prospectus. Prior to investing in our common stock, you should read this prospectus, our filings incorporated by reference herein and the documents we have filed as exhibits to this registration statement of which this prospectus is a part completely and with the understanding that our actual future results may be materially different from what we currently expect.

Except as required by law, we undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. 

INDUSTRY AND MARKET DATA

Unless otherwise indicated, data concerning economic conditions, our industry, our markets and our competitive position are based on a variety of sources, including information from third-party industry analysts, publications, surveys and forecasts and our own estimates and research. These data involve a number of assumptions, estimates and limitations. Industry publications, surveys and forecasts and other public information generally indicate or suggest that their information has been obtained from sources believed to be reliable. None of the third-party industry data used in this prospectus were prepared on our behalf. The industry in which we operate is subject to a high degree of uncertainty and risk due to a variety of factors, including those described in “Risk Factors”. These and other factors could cause results to differ materially from those expressed in these data.

TRADEMARKS

We own or have rights to trademarks or trade names that we use in connection with the operation of our businesses, our corporate names, logos and websites. We may make references to our trademarks and service marks, and to those belonging to other entities. Solely for convenience, trademarks and trade names referred to may appear without ® or ^™ or similar symbols, but such references are not intended to indicate, in any way, that we will not assert, to the fullest extent possible under applicable law, our rights or the rights of the applicable licensor to these trademarks and trade names. We do not intend our use or display of other companies’ trade names, trademarks, or service marks to imply a relationship with, or an endorsement or sponsorship of us by, any other companies. All other trademarks and service marks are the property of their respective owners.