The 2021 Città di Forlì II was a professional tennis tournament played on hard courts. It was the first edition of the tournament which was part of the 2021 ATP Challenger Tour. It took place in Forlì, Italy between 29 November and 5 December 2021.
The following players received wildcards into the singles main draw:
The following players received entry into the singles main draw using protected rankings:
The following player received entry into the singles main draw as a special exempt:
The following players received entry into the singles main draw as alternates:
The following players received entry from the qualifying draw:
