Exhibit 23.1

CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

We consent to the incorporation by reference in this Registration Statement on Form S-3 of our report dated March 16, 2023, relating to the financial statements of Quantum-Si Incorporated, appearing in the Annual Report on Form 10-K of Quantum-Si Incorporated for the year ended December 31, 2022. We also consent to the reference to us under the heading “Experts” in such Registration Statement.

/s/ DELOITTE & TOUCHE LLP

New York, New York

August 11, 2023