T3 Defense Inc.

As filed with the Securities and Exchange Commission on February 11, 2026.

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

UNDER THE SECURITIES ACT OF 1933

T3 Defense Inc.

(Exact name of registrant as specified in its charter)

575 Fifth Ave., 14th Floor

New York, New York 10017

(646) 257-4214

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

Menachem Shalom

T3 Defense Inc.

Chief Executive Officer

575 Fifth Ave., 14th Floor

New York, New York 10017

(646) 257-4214

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

Copies to:

Robert Cohen

McDermott Will & Schulte LLP

333 SE 2nd Avenue, Suite 4500

Miami, Florida 33131

(212) 547-5885

Approximate date of commencement of proposed sale to the public:

As soon as practicable after the effective date hereof.

If any 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, 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 post-effective amendment filed pursuant to Rule 462(d) 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. ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, 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.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities 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 which specifically states that this registration statement shall thereafter become effective in accordance with section 8(a) of the Securities Act of 1933 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.

The information in this prospectus is not complete and may be changed. The selling stockholders may not sell these securities until the registration statement filed with the Securities and Exchange Commission is effective. This prospectus is not an offer to sell these securities and it is not soliciting an offer to buy these securities in any state or jurisdiction where the offer or sale is not permitted.

PRELIMINARY PROSPECTUS

SUBJECT TO COMPLETION, DATED FEBRUARY 11, 2026

T3 Defense Inc.

16,787,988 Shares of Common Stock

This prospectus relates to the resale from time to time by the selling stockholders named in this prospectus, including their transferees, pledgees or donees or their respective successors (collectively, the “Selling Stockholders”), of up to 16,787,988 shares (the “Shares”) of the common stock, par value $0.0001 per share (the “Common Stock”), of T3 Defense Inc. (formerly known as Nukkleus Inc.), a Delaware corporation (the “Company” or “T3 Defense”), which consists of (i) 4,770,340 Shares (the “Common Shares”) and (ii) up to 12,017,648 Shares (the “Warrant Shares”) issuable upon the exercise of a warrant (the “Warrant”). The Common Shares and the Warrant were received by Star 26 Capital, Inc., a Nevada corporation (“Star 26”) as consideration in connection with the Company’s acquisition (the “Acquisition”) of 100% of the issued and outstanding capital stock of Star 26 pursuant to the terms of that certain Amended and Restated Securities Purchase Agreement and Call Option, dated September 15, 2025 (the “Purchase Agreement”), by and among the Company, Star 26, the shareholders of Star 26, and Menachem Shalom, as representative of the shareholders of Star 26. The Acquisition was completed on January 12, 2026 (the “Closing Date”). The Common Shares and the Warrant were subsequently assigned by Star 26 to the Selling Stockholders pro ratably based on their equity ownership in Star 26. The Warrant is exercisable at any time and from time to time until January 12, 2032 at an exercise price of $1.50 per share, subject to adjustment, and is subject to a blocker provision (the “Blocker”), which restricts the exercise of a Warrant if, as a result of such exercise, the holder or any of its affiliates would beneficially own in excess of 9.99% of the number of shares of Common Stock outstanding after giving effect to the issuance of Warrant Shares issuable upon exercise of the Warrant calculated in accordance with Section 13(d) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). For a description of the Acquisition, please see “Prospectus Summary – Company Overview.”

The Shares being registered for resale represent a considerable percentage of our public float, and the sales of such Shares, or the perception that these sales could occur, could cause the market price of the Common Stock to decline significantly. In addition, we are not selling any shares of Common Stock under this prospectus and will not receive any of the proceeds from the sale of Shares by the Selling Stockholders. We are paying the cost of registering the Shares as well as various related expenses. The Selling Stockholders are responsible for all selling commissions, transfer taxes and other costs related to the offer and sale of their Shares. We will, however, receive the net proceeds of the exercise of the Warrant for cash.

The Selling Stockholders may sell the Shares at fixed prices, at market prices prevailing at the time of sale, at prices related to prevailing market prices or at negotiated prices. The Selling Stockholders may sell the Shares to or through underwriters, broker-dealers or agents, who may receive compensation in the form of discounts, concessions or commissions from the Selling Stockholders, the purchasers of the Shares, or both.

Our Common Stock is presently listed on the Nasdaq Global Market (“Nasdaq”) under the symbol “DFNS.” The closing price for our Common Stock on February 10, 2026, as reported by Nasdaq, was $2.21 per share.

We are an “emerging growth company” as the term is used in the Jumpstart Our Business Startups Act of 2012 and, as such, have elected to comply with certain reduced public company reporting requirements for this prospectus and future filings.

Investing in our securities involves a high degree of risk. You should carefully consider the risks and uncertainties described under the heading“Risk Factors” beginning on page 10 of this prospectus before making a decision to purchase our securities.**

NEITHER THE SECURITIES AND EXCHANGE COMMISSION 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 , 2026

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