Filed Pursuant to Rule 424(b)(3)
 Registration No. 333-260528

Prospectus Supplement No. 7
(to prospectus dated November 4, 2021)

Mirion Technologies, Inc.

Up to 8,560,540 Shares of our Class A Common Stock Issuable upon Redemption of Shares of IntermediateCo Class B Common Stock
Up to 27,249,979 Shares of our Class A Common Stock Issuable upon Exercise of Warrants
152,157,565 Shares of our Class A Common Stock for Resale by the Selling Holders

This prospectus supplement is being filed to update and supplement the information contained in the prospectus dated November 4, 2021 (the “Prospectus”), which forms part of our registration statement on Form S-1 (No. 333-260528) with the information contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commission (the “SEC”) on March 3, 2022 (the “Current Report”). Accordingly, we have attached the Current Report to this prospectus supplement.

The Prospectus and this prospectus supplement relate to: (1) the issuance by us of up to an aggregate of 35,810,519 shares of Class A common stock, par value $0.0001 per share (“Class A common stock”), of Mirion Technologies, Inc. (the “Company”) that may be issued upon (i) the exercise of 27,249,979 warrants to purchase Class A common stock at an exercise price of $11.50 per share of Class A common stock, including the public warrants and the private placement warrants (each as defined in the Prospectus), and (ii) the redemption of up to 8,560,540 shares of Class B common stock, par value $0.0001 per share (the “IntermediateCo Class B common stock”), of Mirion IntermediateCo, Inc. (“IntermediateCo”); and (2) the offer and sale, from time to time, by the selling holders identified in the Prospectus (the “Selling Holders”), or their permitted transferees, of up to 152,157,565 shares of Class A common stock.

This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not be delivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectus supplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in the Prospectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Terms used in this prospectus supplement but not defined herein shall have the meanings given to such terms in the Prospectus.

You should read the Prospectus, this prospectus supplement and any additional prospectus supplement or amendment carefully before you invest in our securities. Our Class A common stock and public warrants are listed on The New York Stock Exchange under the symbols “MIR” and “MIR WS,” respectively. On March 2, 2022, the

closing price of our Class A common stock was $8.89 per share and the closing price for our public warrants was $1.9843 per warrant.

Investing in our Class A common stock and warrants involves a high degree of risk. See the section titled “Risk Factors” beginning on page 10 of the Prospectus and in any applicable prospectus supplement.

Neither the SEC nor any other state securities commission has approved or disapproved of these securities or passed on the adequacy or accuracy of the Prospectus or this prospectus supplement. Any representation to the contrary is a criminal offense.

March 3, 2022

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): February 28, 2022

Mirion Technologies, Inc.

(Exact Name of Registrant as Specified in Its Charter)

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 5.02(b). Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On February 28, 2022, Ms. Kipling Matas, who has served as the Principal Accounting Officer of Mirion Technologies, Inc. (the “Company”), resigned from her position, effective March 23, 2022. Mr. Brian Schopfer, Chief Financial Officer, will assume the role of Principal Accounting Officer, effective upon her departure. Ms. Matas has agreed to continue assisting the Company with the transition through May 2022 under a consulting arrangement.

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: March 3, 2022