Mobix Labs Inc-A美股招股说明书(2026-05-22版)

PROSPECTUS SUPPLEMENT NO. 3 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”) ofMobix 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 orincorporated by reference in the Prospectus with the information contained in the Current Report on Form 8-K filed with the Securitiesand Exchange Commission (the “SEC”) on May 19, 2026 and the information contained in the Quarterly Report on Form 10-Q filedwith the SEC on May 20, 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 May 21, 2026, the closing price of our Class A Common Stock was $1.90. Investing in the Company’s Class A Common Stock involves risks. See “Risk Factors” beginning on page 5 of theProspectus 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 theadequacy or accuracy of this prospectus. Any representation to the contrary is a criminal offense. The date of this Prospectus Supplement No. 3 is May 22, 2026 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM 8-K CURRENT REPORTPursuant to Section 13 or 15(d)of the Securities Exchange Act of 1934 Date of report (Date of earliest event reported): May 13, 2026 MOBIX LABS, INC.(Exact name of registrant as specified in its charter) Check the appropriate box below if the Form 8-K is intended to simultaneously satisfy the filing obligation of the registrant under anyof the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) 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). If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Item 1.01 Entry into a Material Definitive Agreement. First Amendment to Securities Purchase Agreement and Convertible Note and Investor Rights Agreement On May 13, 2026, Mobix Labs, Inc. (the “Company”) entered into a first amendment to the securities purchase agreementand senior secured convertible promissory note (the “First Amendment”), with Leviston Resources, LLC (“Leviston”), amending thesenior secured convertible note originally issued on March 31, 2026 (the “Original Note”) to increase the principal amount from $3million to $4 million in exchange for an additional cash advance of $833,333 to the Company. The material terms of the Original Note,including its variable conversion price formula, were previously disclosed in our Current Report on Form 8-K filed with the SEC onApril 3, 2026. Additionally, on May 13, 2026, we entered into the Investor Rights Agreement (the “Investor Rights Agreement”) that grantsLeviston the right, but not the obligation, to acquire, over a seven-month period, additional secured convertible notes of up to $4.0million in aggregate principal amount on terms substantially similar to the Original Note and secured on a pari passu basis. The foregoing descriptions of the First Amendment and the Investor Rights Agreement are qualified in their entirety byreference to the full text of those agreements, copies of which will be filed as exhibits to the Company’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2026. All $4 million of principal under the Original Note has since been satisfied in full through conversion into shares of theCompany’s Class A Common Stock (the “Common Stock”), all of which have been resold by Leviston pursuant to the Company’seffective Registration Statement on Form S-1 (see Item 1.02 below). Leviston at no time beneficially owned in excess of 4.99% of theoutstanding shares of Class A Common Stock. Item 1.02 Termination of a Material Definitive Agreement. On May 18, 2026, the Company satisfied in full the entire $4 mil