Certification Pursuant to Rule 30a-2(b) under the 1940 Act and Section 906 of the
Sarbanes-Oxley Act

I, James M. Dykas, President and Chief Executive Officer of First Trust Senior Floating Rate Income Fund II (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (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 Registrant.

Date:	February 18, 2021	/s/ James M. Dykas
		James M. Dykas, President and Chief Executive Officer (principal executive officer)

I, Donald P. Swade, Treasurer, Chief Financial Officer and Chief Accounting Officer of First Trust Senior Floating Rate Income Fund II (the “Registrant”), certify that:

1. The Form N-CSR of the Registrant (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 Registrant.

Date:	February 18, 2021	/s/ Donald P. Swade
		Donald P. Swade, Treasurer, Chief Financial Officer and Chief Accounting Officer (principal financial officer)