UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)
of the Securities Exchange Act of 1934
Date of Report (Date of earliest event reported): August 21, 2026

MERIDIAN3 INDUSTRIALS ACQUISITION CORP

(Exact Name of Registrant as Specified in its Charter)

Registrant’s telephone number, including area code: (212) 653-0982

Not Applicable

(Former name or former address, if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

Securities registered pursuant to Section 12(b) of the Act:

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging growth company x

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 13(a) of the Exchange Act. ¨

Item 8.01. Other Events.

Separate Trading of Class A Ordinary Shares and Warrants

On August 21, 2026, Meridian3 Industrials Acquisition Corp (the “Company”) announced that, commencing on August 24, 2026, the holders of the units issued by the Company in its initial public offering (the “Units”), each Unit consisting of one Class A ordinary share of the Company, par value $0.0001 per share (the “Class A Ordinary Share”), and one-half of one redeemable warrant of the Company (the “Warrant”), with each whole Warrant entitling the holder thereof to purchase one Class A Ordinary Share for $11.50 per share, may elect to separately trade the Class A Ordinary Shares and the Warrants included in the Units.

Any Units not separated will continue to trade on the Nasdaq Global Market under the symbol “MIACU”. Any underlying shares of Class A Ordinary Shares and Warrants that are separated will trade on the Nasdaq Global Market under the symbols “MIAC” and “MIACW,” respectively. No fractional Warrants will be issued upon separation of the Units and only whole Warrants will trade. Holders of Units will need to have their brokers contact Continental Stock Transfer & Trust Company, the Company’s transfer agent, in order to separate the holders’ Units into Class A Ordinary Shares and Warrants.

A copy of the press release issued by the Company announcing the separate trading of the securities underlying the Units is included hereto as Exhibit 99.1.

Item 9.01 Financial Statements and Exhibits.

(c) Exhibits

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

Date: August 21, 2026