Goldman Sachs Middle Market Lending LLC II 10-Q 2023 Q3 Quarterly report

Exhibit 32.1

Certification of Co-Chief Executive Officer

Pursuant to

18 U.S.C. Section 1350 as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the Quarterly Report on Form 10-Q of Goldman Sachs Middle Market Lending Corp. II (the “Company”) for the quarter ended September 30, 2023 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), Alex Chi, as Co-Chief Executive Officer of the Company, hereby certifies, 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 his knowledge:

1. 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.

Date: November 7, 2023

/s/ Alex Chi

Alex Chi

Co-Chief Executive Officer and Co-President

(Co-Principal Executive Officer)