Filed Pursuant to Rule 424(b)(3) and Rule 424(c)

Registration Statement No. 333-290247

October 22, 2026

PROSPECTUS SUPPLEMENT NO. 7

MOBIX LABS, INC.

Up to 2,412,711 SHARES OF CLASS A COMMON STOCK

This prospectus supplement amends the prospectus dated March 12, 2026 (as supplemented to date, the “Prospectus”) of Mobix Labs, Inc. a Delaware corporation (the “Company”), which forms a part of the Company’s Registration Statement on Form S-1, as amended (No. 333-290247). This prospectus supplement is being filed to update and supplement the information included or incorporated by reference in the Prospectus with the information contained in the Current Report on Form 8-K filed with the Securities and Exchange Commission (the “SEC”) on October 19, 2026, as set forth below. This prospectus supplement should be read in conjunction with the Prospectus, which is to be delivered with this prospectus supplement.

Shares of our Class A Common Stock are listed on the Nasdaq Stock Market LLC (“Nasdaq”) under the symbol “MOBX”. On October 21, 2026, the closing price of our Class A Common Stock was $0.72.

Investing in the Company’s Class A Common Stock involves risks. See “Risk Factors” beginning on page 5 of the Prospectus and under similar headings in any amendments or supplements to the Prospectus.

Neither the SEC nor any other regulatory body 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 Supplement No. 7 is October 22, 2026

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 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): October 14, 2026

MOBIX LABS, INC.

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (949) 808-8888

N/A

(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:

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 ☐

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 1.02. Termination of a Material Definitive Agreement.

On October 14, 2026, Mobix Labs, Inc. (the “Company”) delivered written notice to Vision Aerial, Inc. (“Vision Aerial”) terminating the Agreement and Plan of Merger, dated July 24, 2026 (the “Merger Agreement”), pursuant to Section 8.1(c) thereof, following the expiration of the contractual termination date. The Merger Agreement was previously disclosed in the Company’s Current Report on Form 8-K filed on July 29, 2026.

The termination followed delays in completing certain due diligence and financial reporting matters, including the receipt of financial and accounting information necessary to complete the audit process. The transaction was not consummated within the contemplated timeframe.

The termination was amicable, and the Company maintains a positive relationship with Vision Aerial and remains open to exploring potential opportunities with Vision Aerial in the future.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

SIGNATURES

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.