Exhibit 32.1

CERTIFICATION OF PRINCIPAL EXECUTIVE

OFFICER PURSUANT TO 18 U.S.C

SECTION 1350, AS ADOPTED PURSUANTTO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

I, Peter K. Miller, Chief Executive Officer of OptiNose, Inc. (the “Company”), do hereby certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

1.the Annual Report on Form 10-K of the Company for the year ended December 31, 2020 (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, as amended; and

2.the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company for the periods presented therein.

Date: March 3, 2021 /s/ Peter K. Miller Peter K. Miller Chief Executive Officer (Principal Executive Officer)