# 2021 St. Petersburg Ladies' Trophy – Singles

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

* Ekaterina Alexandrova (quarterfinals)
* Veronika Kudermetova (quarterfinals)
* Fiona Ferro (second round)
* Svetlana Kuznetsova (semifinals)
* Anastasia Pavlyuchenkova (second round)
* Jeļena Ostapenko (second round)
* Kristina Mladenovic (first round)
* Daria Kasatkina (champion)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| WC | Margarita Gasparyan | 6 | 7$^{11}$ | | | | | |
| WC | Vera Zvonareva | 3 | 6$^9$ | | | | | |
| WC | Vera Zvonareva | 3 | 6$^9$ | | WC | Margarita Gasparyan | 3 | 1$^r$ |
| | | | | | 8 | Daria Kasatkina | 6 | 2 |
| 4 | Svetlana Kuznetsova | 6 | 0 | 2 | 8 | Daria Kasatkina | 6 | 2 |
| 8 | Daria Kasatkina | 1 | 6 | 6 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| | | | | | 1 | E Alexandrova | 6 | 6 | | | | | | | | | |
| | S Vögele | 0 | 6 | 4 | | T Martincová | 3 | 4 | | | | | | | | | |
| | T Martincová | 6 | 4 | 6 | | | | | | 1 | E Alexandrova | 2 | 5 | | | | |
| | K Siniaková | 6 | 6 | | | | | | | WC | M Gasparyan | 6 | 7 | | | | |
| | K Flipkens | 1 | 2 | | | K Siniaková | 4 | 4 | | | | | | | | | |
| WC | M Gasparyan | 6$^1$ | 6 | 6 | WC | M Gasparyan | 6 | 6 | | | | | | | | | |
| 7 | K Mladenovic | 7$^7$ | 1 | 1 | | | | | | | | | | WC | M Gasparyan | 6 | 7$^{11}$ |
| | | | | | | | | | | | | | | WC | V Zvonareva | 3 | 6$^9$ |
| | | | | | 3 | F Ferro | 7$^8$ | 5 | 6$^2$ | | | | | | | | |
| Q | Ar Rodionova | 1 | 3 | | WC | V Zvonareva | 6$^6$ | 7 | 7$^7$ | | | | | | | | |
| WC | V Zvonareva | 6 | 6 | | | | | | | WC | V Zvonareva | 6 | 6 | | | | |
| | K Zavatska | 2 | 7$^8$ | 5 | | | | | | Q | A Gasanova | 3 | 1 | | | | |
| Q | A Gasanova | 6 | 6$^6$ | 7 | Q | A Gasanova | 1 | 7$^{10}$ | 7$^7$ | | | | | | | | |
| LL | Ç Büyükakçay | 4 | 4 | | 5 | A Pavlyuchenkova | 6 | 6$^8$ | 6$^4$ | | | | | | | | |
| 5 | A Pavlyuchenkova | 6 | 6 | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | J Ostapenko | 6 | 6 | | | | | | | | | | | | | | | | |
| | P Badosa | 2 | 2 | | 6 | J Ostapenko | 3 | 6$^9$ | | | | | | | | | | | |
| Q | J Cristian | 6$^3$ | 6 | 2 | Q | J Cristian | 6 | 7$^{11}$ | | | | | | | | | | | |
| PR | V Lapko | 7$^7$ | 4 | 1$^r$ | | | | | | Q | J Cristian | 7$^7$ | 3 | 3 | | | | | |
| Q | Xin Wang | 6 | 5 | 7 | | | | | | 4 | S Kuznetsova | 6$^5$ | 6 | 6 | | | | | |
| | V Tomova | 1 | 7 | 5 | Q | Xin Wang | 1 | 5 | | | | | | | | | | | |
| | | | | | 4 | S Kuznetsova | 6 | 7 | | | | | | | | | | | |
| | | | | | | | | | | | | | | | 4 | S Kuznetsova | 6 | 0 | 2 |
| 8 | D Kasatkina | 6 | 7$^7$ | | | | | | | | | | | | 8 | D Kasatkina | 1 | 6 | 6 |
| Q | C Tauson | 4 | 6$^0$ | | 8 | D Kasatkina | 5 | 6 | 7$^7$ | | | | | | | | | | |
| | A Bogdan | 6 | 2 | 1 | | A Sasnovich | 7 | 3 | 6$^2$ | | | | | | | | | | |
| | A Sasnovich | 2 | 6 | 6 | | | | | | 8 | D Kasatkina | 1 | 6 | 6 | | | | | |
| WC | D Mishina | 1 | 7$^7$ | 1 | | | | | | 2 | V Kudermetova | 6 | 1 | 2 | | | | | |
| Q | K Rakhimova | 6 | 6$^2$ | 6 | Q | K Rakhimova | 5 | 6 | 6$^5$ | | | | | | | | | | |
| | | | | | 2 | V Kudermetova | 7 | 3 | 7$^7$ | | | | | | | | | | |

## Qualifying
### Seeds

* Clara Tauson (qualified)
* Viktoriya Tomova (moved to main draw)
* Monica Niculescu (first round)
* Natalia Vikhlyantseva (first round)
* Kamilla Rakhimova (qualified)
* Wang Xinyu (qualified)
* Jaqueline Cristian (qualified)
* Magdalena Fręch (qualifying competition)
* Arina Rodionova (qualified)
* Çağla Büyükakçay (qualifying competition, lucky loser)
* Lesley Pattinama Kerkhove (qualifying competition)
* Laura Ioana Paar (first round)

### Qualifiers

* Clara Tauson
* Jaqueline Cristian
* Anastasia Gasanova
* Arina Rodionova
* Kamilla Rakhimova
* Wang Xinyu

### Lucky loser

* Çağla Büyükakçay

### Qualifying draw
#### First qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Clara Tauson | 7 | 6 | | | | | |
| WC | Ekaterina Shalimova | 5 | 3 | | | | | |
| WC | Ekaterina Shalimova | 5 | 3 | | 1 | Clara Tauson | 7 | 6 |
| | | | | | 11 | Lesley Pattinama Kerkhove | 5 | 2 |
| | Ekaterine Gorgodze | 6 | 6$^0$ | 3 | 11 | Lesley Pattinama Kerkhove | 5 | 2 |
| 11 | Lesley Pattinama Kerkhove | 0 | 7$^7$ | 6 | | | | |

#### Second qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| Alt | Sofya Lansere | 3 | 0 | | | | | |
| WC | Alina Charaeva | 6 | 6 | | | | | |
| WC | Alina Charaeva | 6 | 6 | WC | Alina Charaeva | 6 | 1 | 2 |
| | | | | 7 | Jaqueline Cristian | 4 | 6 | 6 |
| | Natalija Kostić | 1 | 3 | 7 | Jaqueline Cristian | 4 | 6 | 6 |
| 7 | Jaqueline Cristian | 6 | 6 | | | | | |

#### Third qualifier

| First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 3 | Monica Niculescu | 3 | 4 | | | | |
| WC | Ana Konjuh | 6 | 6 | | | | |
| WC | Ana Konjuh | 6 | 6 | WC | Ana Konjuh | 4 | 3 |
| | | | | | Anastasia Gasanova | 6 | 6 |
| | Anastasia Gasanova | 6 | 6 | | Anastasia Gasanova | 6 | 6 |
| 12 | Laura Ioana Paar | 4 | 3 | | | | |

#### Fourth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Natalia Vikhlyantseva | 6 | 4 | 1 | | | | |
| | Valeria Savinykh | 2 | 6 | 6 | | | | |
| | Valeria Savinykh | 2 | 6 | 6 | | Valeria Savinykh | 3 | 4 |
| | | | | | 9 | Arina Rodionova | 6 | 6 |
| | Kathinka von Deichmann | 4 | 4 | | 9 | Arina Rodionova | 6 | 6 |
| 9 | Arina Rodionova | 6 | 6 | | | | | |

#### Fifth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 5 | Kamilla Rakhimova | 6 | 4 | 6 | | | | | |
| | Aleksandra Krunić | 2 | 6 | 4 | | | | | |
| | Aleksandra Krunić | 2 | 6 | 4 | 5 | Kamilla Rakhimova | 6 | 2 | 6 |
| | | | | | 8 | Magdalena Fręch | 3 | 6 | 2 |
| WC | Polina Kudermetova | 1 | 3 | | 8 | Magdalena Fręch | 3 | 6 | 2 |
| 8 | Magdalena Fręch | 6 | 6 | | | | | | |

#### Sixth qualifier

| First round | First round | First round | First round | First round | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 6 | Wang Xinyu | 6 | 6 | | | | | |
| | Marina Melnikova | 2 | 3 | | | | | |
| | Marina Melnikova | 2 | 3 | | 6 | Wang Xinyu | 6 | 6 |
| | | | | | 10 | Çağla Büyükakçay | 2 | 3 |
| | Jana Fett | 3 | 6 | 5 | 10 | Çağla Büyükakçay | 2 | 3 |
| 10 | Çağla Büyükakçay | 6 | 4 | 7 | | | | |