Matteo Berrettini defeated Aslan Karatsev in the final, 6–1, 3–6, 7–6(7–0) to win the men's singles tennis title at the 2021 Serbia Open.
Andreas Seppi was the reigning champion from when the event was last held in 2012, but he decided not to participate this year.
Seeds The top four seeds received a bye into the second round.
Draw
Finals
Top half
Bottom half
Qualifying
Seeds
Qualifiers
Lucky losers
Qualifying draw
First qualifier
Second qualifier
Third qualifier
Fourth qualifier
References
External links Main draw Qualifying draw