Albert Ramos Viñolas defeated Cameron Norrie in the final, 4–6, 6–3, 7–6(7–3) to win the singles tennis title at the 2021 Estoril Open. It marked his third career ATP Tour singles title, all of which have been on clay. Norrie was aiming to win his first ATP Tour title in his second final.
Stefanos Tsitsipas was the defending champion from when the tournament was last held in 2019, but did not return to compete.
Seeds The top four seeds received a bye into the second round.
Draw
Finals
Top half
Bottom half
Qualifying
Seeds
Qualifiers
Lucky loser
Qualifying draw
First qualifier
Second qualifier
Third qualifier
Fourth qualifier
References
External links Main draw Qualifying draw