Daria Kasatkina won the women's singles title at the 2021 St. Petersburg Ladies' Trophy, after Margarita Gasparyan retired from the final with the scoreline at 6–3, 2–1.
Kiki Bertens was the two-time defending champion, but she chose not to participate.
This was the first tournament since Oakland in 1993 in which seven of the eight quarterfinalists were all from the same country. It was also the first tournament in WTA history in which all four semifinalists represented Russia.
Seeds
Draw
Finals
Top half
Bottom half
Qualifying
Seeds
Qualifiers
Lucky loser
Qualifying draw
First qualifier
Second qualifier
Third qualifier
Fourth qualifier
Fifth qualifier
Sixth qualifier
References
External links Main draw Qualifying draw