2021 Internazionali di Tennis Città di Forlì

Country	Player	Rank1	Seed
NED	Tallon Griekspoor	131	1
ITA	Alessandro Giannessi	159	2
ITA	Paolo Lorenzi	167	3
CAN	Steven Diez	190	4
TUR	Cem İlkel	199	5
NED	Robin Haase	205	6
ARG	Tomás Martín Etcheverry	220	7
FRA	Quentin Halys	223	8

• ¹ Rankings as of 31 May 2021.^[1]

The following players received wildcards into the singles main draw:

• Jacopo Berrettini
• Flavio Cobolli
• Francesco Passaro

The following player received entry into the singles main draw using a protected ranking:

• Viktor Galović

The following players received entry into the singles main draw as alternates:

• Raúl Brancaccio
• Orlando Luz

The following players received entry from the qualifying draw:

• Sebastian Fanselow
• Francesco Forti
• Lucas Gerch
• Thiago Agustín Tirante

• Mats Moraing def. Quentin Halys 3–6, 6–1, 7–5.

• Sergio Galdós / Orlando Luz def. Pedro Cachin / Camilo Ugo Carabelli 7–5, 2–6, [10–8].