Exhibit 31.3

CERTIFICATION PURSUANT TO RULES 13a-14(a) AND 15d-14(a) UNDER THE SECURITIES EXCHANGE
ACT OF 1934, AS ADOPTED PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Ryan Martin, certify that:

1. I have reviewed this Amendment No. 1 to Annual Report on Form 10-K/A of Fathom Digital Manufacturing Corporation; and

2. Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report.

Date: May 1, 2023	By:	/s/ Ryan Martin
		Ryan Martin
		Chief Executive Officer