Firefly Aerospace Inc.

As filed with the Securities and Exchange Commission on November 17, 2025

No.

333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

1320 Arrow Point Drive #109

Cedar Park

,

TX

893-5570

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

Jason Kim

Chief Executive Officer

1320 Arrow Point Drive #109

Cedar Park

, TX

512-

893-5570

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

Copies of all communications, including communications sent to agent for service, should be sent to:

Approximate date of commencement of proposed sale to the public

: From time to time after this Registration Statement becomes effective.

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, check the following box: ☒

If this Form is filed to registered 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, 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 Securities Exchange Act of 1934. (Check one):

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 of 1933.☐

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 this 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. We 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 offers to buy these securities, in any jurisdiction where the offer or sale is not permitted.

PROSPECTUS (Subject to Completion)

Dated November 17, 2025

11,111,116 Shares

This prospectus relates to the offer and sale from time to time by the selling securityholders named in this prospectus (the “Selling Securityholders”) of up to 11,111,116 shares of Common Stock, par value $0.0001 per share (the “Common Stock”) of Firefly Aerospace Inc. (“Firefly Aerospace”) that were received by such Selling Securityholders as consideration in connection with Firefly Aerospace’s acquisition (the “Acquisition”) of SciTec Innovations, LLC, a Delaware limited liability company. In connection with the Acquisition, the Common Stock acquired by the Selling Securityholders was valued at $555.6 million based on a price of $50.00 per share of Common Stock.

We will not receive any proceeds from the sale of shares of Common Stock by the Selling Securityholders pursuant to this prospectus. However, we will pay the expenses, other than underwriting discounts and commissions and certain expenses incurred by the Selling Securityholders in connection with the registration of the Common Stock.

We are registering the offer and sale of certain securities described above to satisfy certain registration rights we have granted. Our registration of the securities covered by this prospectus does not mean that the Selling Securityholders will offer or sell, any of the securities. The Selling Securityholders and any of their permitted transferees may offer and sell the securities covered by this prospectus in a number of different ways and at varying prices. In connection with the Acquisition, the Selling Securityholders have agreed not to transfer, sell, pledge, distribute or otherwise dispose of the Common Stock received in the Acquisition, or enter into any other arrangement that transfers to another person any of the economic consequences of ownership of such shares, until February 7, 2026. Additional information on the Selling Securityholders, and the times and manner in which they may offer and sell the securities under this prospectus, is provided under “Selling Securityholders” and “Plan of Distribution” in this prospectus.

You should read this prospectus and any prospectus supplement or amendment carefully before you invest in our securities.

Our Common Stock is listed on the Nasdaq Global Market under the symbol “FLY”. On November 12, 2025, the closing price of our Common Stock was $18.31 per share.

We are an “emerging growth company” as that term is used in the Jumpstart Our Business Startups Act of 2012 (the “JOBS Act”) and have elected to comply with certain reduced public company reporting requirements. See “Risk Factors” and “Prospectus Summary—Implications of Being an Emerging Growth Company.”

Investing in our Common Stock involves risks. See “Risk Factors” beginning on page 8 to read about factors you should consider before buying shares of our Common Stock.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

Prospectus dated , 2025.