# 2021 Reinert Open – Singles

Nina Stojanović was the defending champion but chose to compete at the 2020 Summer Olympics instead.
Lucky loser Elina Avanesyan won the title, defeating Federica Di Sarra in the final, 6–7$^{(4–7)}$, 6–2, 6–2.

## Seeds

* Tamara Korpatsch (second round)
* Lara Arruabarrena (second round)
* Julia Grabher (second round)
* Daniela Seguel (first round)
* Katharina Gerlach (first round)
* Alycia Parks (first round)
* Richèl Hogenkamp (second round)
* Marie Benoît (first round)

## 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 | Final |
| LL | Elina Avanesyan | 7 | 7$^8$ | | | | | | |
| | Mirjam Björklund | 5 | 6$^6$ | | | | | | |
| | Mirjam Björklund | 5 | 6$^6$ | | LL | Elina Avanesyan | 6$^4$ | 6 | 6 |
| | | | | | | Federica Di Sarra | 7$^7$ | 2 | 2 |
| | Federica Di Sarra | 3 | 6 | 6 | | Federica Di Sarra | 7$^7$ | 2 | 2 |
| Q | Cristiana Ferrando | 6 | 4 | 3 | | | | | |

### 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 | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | T Korpatsch | 6 | 6 | | | | | | | | | | | | | | | |
| Q | A Hartono | 4 | 3 | | 1 | T Korpatsch | 6 | 6$^3$ | 0 | | | | | | | | | |
| | K Stewart | 6$^4$ | 4 | | LL | E Avanesyan | 4 | 7$^7$ | 6 | | | | | | | | | |
| LL | E Avanesyan | 7$^7$ | 6 | | | | | | | LL | E Avanesyan | 7 | 4 | 6 | | | | |
| | S Mendez | 1 | 6 | 1 | | | | | | | A Danilina | 5 | 6 | 3 | | | | |
| | A Danilina | 6 | 4 | 6 | | A Danilina | 6$^4$ | 6 | 6 | | | | | | | | | |
| PR | K Hobgarski | 4 | 6 | 6 | PR | K Hobgarski | 7$^7$ | 3 | 2 | | | | | | | | | |
| 6 | A Parks | 6 | 4 | 2 | | | | | | | | | | | LL | E Avanesyan | 7 | 7$^8$ |
| 3 | J Grabher | 6 | 3 | | | | | | | | | | | | | M Björklund | 5 | 6$^6$ |
| Q | E Makarova | 0 | 1$^r$ | | 3 | J Grabher | 2 | 6$^7$ | | | | | | | | | | |
| | M Di Giuseppe | 3 | 6 | 1 | Q | K Bartone | 6 | 7$^7$ | | | | | | | | | | |
| Q | K Bartone | 6 | 4 | 6 | | | | | | Q | K Bartone | 4 | 1 | | | | | |
| Q | F Arcidiacono | 3 | 6 | 3 | | | | | | | M Björklund | 6 | 6 | | | | | |
| | M Caregaro | 6 | 3 | 6 | | M Caregaro | 1 | 1 | | | | | | | | | | |
| | M Björklund | 6 | 6 | | | M Björklund | 6 | 6 | | | | | | | | | | |
| 5 | K Gerlach | 4 | 2 | | | | | | | | | | | | | | | |

### 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 | Semifinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 8 | M Benoît | 4 | 2 | | | | | | | | | | | | | | | |
| Q | J Bouzas Maneiro | 6 | 6 | | Q | J Bouzas Maneiro | 6 | 2 | 3 | | | | | | | | | |
| PR | J Fourlis | 6 | 4 | 7 | PR | J Fourlis | 1 | 6 | 6 | | | | | | | | | |
| Q | E Halbauer | 3 | 6 | 5 | | | | | | PR | J Fourlis | 3 | 4 | | | | | |
| | F Di Sarra | 6 | 6 | | | | | | | | F Di Sarra | 6 | 6 | | | | | |
| WC | N Noha Akugue | 1 | 1 | | | F Di Sarra | 6 | 6 | | | | | | | | | | |
| Q | A Klasen | 6 | 6$^5$ | 6 | Q | A Klasen | 4 | 4 | | | | | | | | | | |
| 4 | D Seguel | 3 | 7$^7$ | 4 | | | | | | | | | | | F Di Sarra | 3 | 6 | 6 |
| 7 | R Hogenkamp | 6 | 7$^7$ | | | | | | | | | | | Q | C Ferrando | 6 | 4 | 3 |
| WC | Jo Steur | 4 | 6$^2$ | | 7 | R Hogenkamp | 6$^1$ | 2 | | | | | | | | | | |
| PR | A Zaja | 6 | 3 | 6 | PR | A Zaja | 7$^7$ | 6 | | | | | | | | | | |
| | S Shapatava | 1 | 6 | 1 | | | | | | PR | A Zaja | 1 | 3 | | | | | |
| Q | C Ferrando | 6 | 6 | | | | | | | Q | C Ferrando | 6 | 6 | | | | | |
| WC | N Rivkin | 1 | 3 | | Q | C Ferrando | 6 | 6 | | | | | | | | | | |
| WC | N Schunk | 3 | 2 | | 2 | L Arruabarrena | 1 | 2 | | | | | | | | | | |
| 2 | L Arruabarrena | 6 | 6 | | | | | | | | | | | | | | | |