Iron Dome Acquisition I Corp.

As filed with the Securities and Exchange Commission on January 30, 2026

Registration No. 333-

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORMS-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

(Exact name of registrant as specified in its charter)

244 Fifth Avenue, Suite #1814

New York, New York 10001

(410) 671-5481

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

Tom Y. Livne

Chief Executive Officer

c/o Iron Dome Acquisition I Corp.

244 Fifth Avenue, Suite #1814

New York, New York 10001

(410) 671-5481

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

Copies to:

Approximate date of commencement of proposed sale to the public:

As soon as practicable after the effective date of this registration statement.

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 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, 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.

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, as amended, 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 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.

SUBJECT TO COMPLETION, DATED JANUARY 30, 2026

PROSPECTUS

20,000,000 Units

Iron Dome Acquisition I Corp. is a newly incorporated blank check company for the purpose of effecting a merger, amalgamation, share exchange, asset acquisition, share purchase, reorganization or similar business combination with one or more businesses, which we refer to throughout this prospectus as our initial business combination. We have not selected any specific business combination target and we have not, nor has anyone on our behalf, engaged in any substantive discussions, directly or indirectly, with any business combination target with respect to an initial business combination with us.

This is an initial public offering of our securities. Each unit has an offering price of $10.00 and consists of one Class A ordinary share and one-third of one redeemable warrant. Each whole warrant entitles the holder thereof to purchase one Class A ordinary share at a price of $11.50 per share, subject to adjustment as described in this prospectus. Only whole warrants are exercisable. The warrants will become exercisable on the later of the completion of our initial business combination (the “warrant exercise date”) or 12 months after this registration statement is declared effective by the Securities and Exchange Commission and will expire five years after the completion of our initial business combination or earlier upon redemption or liquidation (the “warrant expiration date”), as described in this prospectus. This prospectus also relates to the issuance of an aggregate of 7,666,666 Class A ordinary shares issuable upon exercise of such warrants. We have also granted the underwriters a 45-day option to purchase up to an additional 3,000,000 units to cover over-allotments, if any.

We will provide our public shareholders with the opportunity to redeem, regardless of whether they abstain, vote for, or vote against, our initial business combination, all or a portion of their Class A ordinary shares upon the completion of our initial business combination at a per share price, payable in cash, equal to the aggregate amount then on deposit in the trust account described below calculated as of two business days prior to the consummation of our initial business combination, including interest, divided by the number of then outstanding public shares, subject to the limitations described herein. Notwithstanding the foregoing redemption rights, if we seek shareholder approval of our initial business combination and we do not conduct redemptions in connection with our initial business combination pursuant to the tender offer rules, our amended and restated memorandum and articles of association will provide that a public shareholder, together with any affiliate of such shareholder or any other person with whom such shareholder is acting in concert or as a “group” (as defined under Section 13 of the Securities Exchange Act of 1934, as amended), is restricted from redeeming its shares with respect to more than an aggregate of 15% of the shares sold in this offering, without our prior consent. We will have 24 months from the closing of this offering to consummate an initial business combination. In addition, our shareholders can vote at any time to amend our amended and restated memorandum and articles of association to extend the amount of time we will have to complete an initial business combination, in each case as further described herein. There is no limit on the number of times our shareholders can vote to amend our amended and restated memorandum and articles of association to extend the amount of time we will have to complete an initial business combination and any such extension may be for any amount of time. We refer to the time period we have to complete an initial business combination, as it may be extended as described above, as the “completion window”. If our completion window is extended by an amendment to our amended and restated memorandum and articles of association, our shareholders will be entitled to vote on such amendment and to redeem their shares in connection with any such extension regardless of whether they abstain, vote in favor of or vote against such extension.

If we have not completed our initial business combination within the completion window or we do not otherwise seek shareholder approval to amend our amended and restated memorandum and articles of association to further extend the time to complete our initial business combination, we will redeem 100% of the public shares at a per share price, payable in cash, equal to the aggregate amount then on deposit in the trust account, including interest (less any permitted withdrawals and up to $100,000 of interest to pay dissolution expenses), divided by the number of then outstanding public shares, subject to applicable law and certain conditions as further described herein. Please see “Redemption of Public Shares and Liquidation if no Initial Business Combination” on page 126 for more information.

Prior to this offering, there has been no public market for our units, Class A ordinary shares or warrants. We intend to apply to list our units on the Nasdaq Stock Market (“Nasdaq”) under the symbol “IDACU” on or promptly after the date of this prospectus. The Class A ordinary shares and warrants constituting the units will begin separate trading on the 52 nd day following the date of this prospectus (or, if such date is not a business day, the following business day), subject to certain conditions. Once the securities constituting the units begin separate trading, we expect that the Class A ordinary shares and warrants will be listed on the Nasdaq under the symbols “IDAC” and “IDACW,” respectively.

We are an “emerging growth company” and a “smaller reporting company” under applicable federal securities laws and will be subject to reduced public company reporting requirements. Investing in our securities involves risks. Please see “Risk Factors” on page 45. Investors will not be entitled to protections normally afforded to investors in Rule 419 blank check offerings.

(1) The underwriters will immediately reimburse us for the full underwriting discount at closing of this offering; as a result, no net underwriting discount will be retained by the underwriters from the offering proceeds, and the total proceeds, before expenses, to us is $200,000,000. The underwriters will receive compensation upon the closing of this offering, including 200,000 Class A ordinary shares. See “Underwriting” for a description of compensation and other items of value payable to the underwriters.

Of the proceeds we receive from this offering and the sale of the private placement warrants described in this prospectus, $200,000,000, or $230,000,000 if the underwriters’ option to purchase additional units is exercised in full ($10.00 per unit in either case), will be deposited into a U.S.-based trust account with Odyssey Transfer and Trust Company, LLC acting as trustee. Except with respect to interest earned on the funds held in the trust account that may be released to us as described below, the funds held in the trust account will not be released from the trust account until the earliest of: (1) the completion of our initial business combination; (2) the redemption of any public shares properly submitted in connection with a shareholder vote to amend our amended and restated memorandum and articles of association (i) to modify the substance or timing of our obligation to provide for the redemption of our public shares in connection with an initial business combination or to redeem 100% of our public shares if we have not consummated our initial business combination within the completion window or (ii) with respect to any other provision relating to shareholders’ rights or pre-initial business combination activity; and (3) the redemption of all of our public shares if we are unable to complete our initial business combination within the completion window, subject to applicable law. The proceeds deposited in the trust account could become subject to the claims of our creditors, if any, which could have priority over the claims of our public shareholders. We are permitted to withdraw 5% of the interest earned on the trust account to fund our working capital requirements and/or to pay our taxes, and such withdrawals can only be made from interest and not from the principal held in the trust account (“permitted withdrawals”).

Our sponsor, Iron Dome Acquisition I Parent LLC, initially purchased an aggregate of 7,733,333 founder shares (up to 1,000,000 of which are subject to forfeiture by the holders thereof depending on the extent to which the underwriters’ over-allotment option is exercised) for an aggregate purchase price of $25,000, or approximately $0.0032 per share. These Class B ordinary shares will automatically convert into Class A ordinary shares at the time of our initial business combination, or at any time prior thereto at the option of the holder thereof, on a one-for-one basis, subject to adjustment as provided herein. In the case that additional Class A ordinary shares, or equity-linked securities (as described herein), are issued or deemed issued in excess of the amounts issued in this offering and related to the closing of our initial business combination, the ratio at which the Class B ordinary shares will convert

into Class A ordinary shares will be adjusted (unless the holders of a majority of the issued and outstanding Class B ordinary shares agree to waive such anti-dilution adjustment with respect to any such issuance or deemed issuance) so that the number of Class A ordinary shares issuable upon conversion of all Class B ordinary shares will equal, in the aggregate, 25% of the sum of all Class A ordinary shares issued and outstanding upon the completion of this offering, plus all Class A ordinary shares and equity-linked securities issued or deemed issued subsequent to the completion of this offering, excluding any Class A ordinary shares, subject to vesting and any other restrictions, issued or deemed issued to (i) our sponsor (or its members or affiliates) in connection with the consummation of this offering, (ii) any seller in the initial business combination, (iii) the Class A ordinary shares underlying the private placement warrants and (iv) any Class A ordinary shares issued to our sponsor (or its members or affiliates) upon conversion of working capital loans. If we increase or decrease the size of this offering we will effect a capitalization or share repurchase or redemption or other appropriate mechanism, as applicable, with respect to our Class B ordinary shares immediately prior to the consummation of the offering in such amount as to maintain the ownership of our initial shareholders at 25% of the issued and outstanding ordinary shares upon the consummation of this offering. Our public shareholders may incur material dilution due to such anti-dilution adjustments that result in the issuance of Class A ordinary shares on a greater than one-to-one basis upon conversion. Prior to the closing of our initial business combination, only holders of our Class B ordinary shares (i) will have the right to vote to appoint and remove directors prior to or in connection with the completion of our initial business combination and (ii) will be entitled to vote on continuing our company in a jurisdiction outside the Cayman Islands (including any special resolution required to adopt new constitutional documents as a result of our approving a transfer by way of continuation in a jurisdiction outside the Cayman Islands). On any other matters submitted to a vote of our shareholders prior to or in connection with the completion of our initial business combination, holders of the Class B ordinary shares and holders of the Class A ordinary shares will vote together as a single class, except as required by law. See “Summary — Our Sponsor” on page 8, “Summary — The Offering — Founder shares” on page 20, “Summary — The Offering — Transfer restrictions on founder shares” on page 22, “Summary — The Offering — Founder shares conversion and anti-dilution rights” on page 23, “Summary — The Offering — Appointment and removal of directors and continuing the company outside of the Cayman Islands; voting rights” on page 23, “Risk Factors — Risks Relating to our Sponsor and Management Team — The nominal purchase price paid by our sponsor for the founder shares may significantly dilute the implied value of your public shares in the event we consummate an initial business combination, and our sponsor is likely to make a substantial profit on its investment in us in the event we consummate an initial business combination, even if the business combination causes the trading price of our ordinary shares to decline materially” on page 68, “— Risks Relating to our Securities — We may issue additional ordinary shares or preference shares to complete our initial business combination or under an employee incentive plan after completion of our initial business combination. We may also issue Class A ordinary shares upon the conversion of the Class B ordinary shares at a ratio greater than one-to-one at the time of our initial business combination as a result of the anti-dilution provisions contained in our amended and restated memorandum and articles of association. Any such issuances would dilute the interest of our shareholders and likely present other risks” on page 78, “— Our sponsor and certain director, and officers, either directly or indirectly, paid an aggregate of $25,000, or approximately $0.0032 per founder share, and, accordingly, you will experience immediate and substantial dilution from the purchase of our Class B ordinary shares” on page 79, and “— Unlike many other similarly structured blank check companies, our initial shareholders will receive additional Class A ordinary shares if we issue shares to consummate an initial business combination” on page 79 and “Proposed Business — Our Sponsor” on page 110 for more information.

In addition, our sponsor will subscribe to purchase an aggregate of 2,000,000 private placement warrants (whether or not the over-allotment option is exercised) each exercisable to purchase one Class A ordinary share at $11.50 per share, subject to adjustment, at a price of $1.00 per warrant, in a private placement that will close simultaneously with the closing of this offering. Each private placement warrant is exercisable to purchase one Class A ordinary share at $11.50 per share.

Commencing on the date on which our securities are listed on the Nasdaq, we may pay our sponsor or an affiliate of our sponsor up to $25,000 per month for office space, administrative and shared personnel support services. See “Summary — Our Sponsor” on page 8 for more information. In the event that following this offering we obtain working capital loans from our sponsor to finance transaction costs related to our initial business combination, up to $2,000,000 of such loans may be convertible into Class A ordinary shares of the post-business combination entity at a price of $10.00 per share at the option of our sponsor. In addition, after the completion of this offering, our board of directors may approve additional working capital loans for the purpose of funding working capital, which loans may be converted into shares of the post-business combination entity at a price of $10.00 per share.

Because our sponsor and certain director and officers, either directly or indirectly, acquired the founder shares at a nominal price, our public shareholders will incur immediate and substantial dilution upon the closing of this offering, assuming no value is ascribed to the warrants included in the units. Additionally, the Class A ordinary shares issuable in connection with the conversion of the founder shares may result in material dilution to our public shareholders due to the anti-dilution rights of our founder shares that may result in an issuance of Class A ordinary shares on a greater than one-to-one basis upon conversion. Further, the Class A ordinary shares issuable in connection with the exercise of the private placement warrants, including those private placement warrants converted from working capital loans (as described in this prospectus), may result in material dilution to our public shareholders if the $11.50 exercise price of the private placement warrants is significantly less than the market price of our shares at the time such private placement warrants are exercised or if the private placement warrants are exercised on a cashless basis given that the cashless exercise of the warrants will not result in any cash proceeds to us. See “Risk Factors — Risks Relating to our Sponsor and Management Team — The nominal purchase price paid by our sponsor for the founder shares may significantly dilute the implied value of your public shares in the event we consummate an initial business combination, and our sponsor is likely to make a substantial profit on its investment in us in the event we consummate an initial business combination, even if the business combination causes the trading price of our ordinary shares to decline materially” on page 68, “— Risks Relating to our Securities — We may issue additional ordinary shares or preference shares to complete our initial business combination or under an employee incentive plan after completion of our initial business combination. We may also issue Class A ordinary shares upon the conversion of the Class B ordinary shares at a ratio greater than one-to-one at the time of our initial business combination as a result of the anti-dilution provisions contained in our amended and restated memorandum and articles of association. Any such issuances would dilute the interest of our shareholders and likely present other risks” on page 78, “— Our sponsor and certain director, and officers, either directly or indirectly, paid an aggregate of $25,000, or approximately $0.0032 per founder share, and, accordingly, you will experience immediate and substantial dilution from the purchase of our Class B ordinary shares” on page 79 and “— Unlike many other similarly structured blank check companies, our initial shareholders will receive additional Class A ordinary shares if we issue shares to consummate an initial business combination” on page 79; See also “Description of Securities — Warrants — Private Placement Warrants” on page 163.

The following table illustrates the difference between the public offering price and our net tangible book value (NTBV), as adjusted to give effect to this offering and to redemptions of our public shares at varying levels, assuming the full exercise and no exercise of the over-allotment option. See “Summary — Dilution” on page 41 and “Dilution” on page 97 for more information.

Our sponsor, members of our management team and our independent directors will directly or indirectly own our securities following this offering, and accordingly, they may have a conflict of interest in determining whether a particular target business is an appropriate business with which to effectuate our initial business combination. Further, each of our officers and directors may have a conflict of interest with respect to evaluating a particular business combination if the retention or resignation of any such officers and directors was included by a target business as a condition to any agreement with respect to our initial business combination. Additionally, each of our officers and directors now or in the future has or may have additional, fiduciary, contractual or other obligations or duties to one or more other entities pursuant to which such officer or director is or will be required to present a business combination opportunity to such entities. As a result, there may be actual or potential material conflicts of interest between our sponsor and members of our management team on one hand, and purchasers in this offering on the other. See “Summary — The Offering — Conflicts of interest” on page 37, “Proposed Business — Our Sponsor” on page 110, “Proposed Business — Our Acquisition Process” on page 113 and “Management — Conflicts of Interest” on page 144.

The underwriters are offering the units for sale on a firm commitment basis. The underwriters expect to deliver the units to the purchasers on or about , 2026.

Neither the SEC 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.

No offer or invitation, whether directly or indirectly, is being or may be made to the public in the Cayman Islands to subscribe for any of our securities.

Joint Book-Running Managers

The date of this prospectus is , 2026.

We are responsible for the information contained in this prospectus. We have not authorized anyone to provide any information or to make any representations other than those contained in this prospectus. We and the underwriters take no responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus is an offer to sell only the units offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. The information contained in this prospectus is current only as of its date.