# 2021 Engie Open Andrézieux-Bouthéon 42 – Singles

Ysaline Bonaventure was the defending champion, but chose not to participate.
Harmony Tan won the title, defeating Jaqueline Cristian in the final, 3–6, 6–2, 6–1.

## Seeds

* Océane Dodin (second round)
* Anna-Lena Friedsam (quarterfinals)
* Stefanie Vögele (second round)
* Katarina Zavatska (quarterfinals)
* Tereza Martincová (second round)
* Tamara Korpatsch (first round)
* Viktoriya Tomova (second round)
* Clara Tauson (second 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 | Final | Final | Final | Final | Final |
| Q | Urszula Radwańska | 3 | 1 | | | | | |
| | Jaqueline Cristian | 6 | 6 | | | | | |
| | Jaqueline Cristian | 6 | 6 | | Jaqueline Cristian | 6 | 2 | 1 |
| | | | | WC | Harmony Tan | 3 | 6 | 6 |
| WC | Harmony Tan | 6 | 6 | WC | Harmony Tan | 3 | 6 | 6 |
| Q | Kathinka von Deichmann | 1 | 0 | | | | | |

### 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 | O Dodin | 6 | 6 | | | | | | | | | | | | | | | |
| Q | S Bandecchi | 3 | 3 | | 1 | O Dodin | 3 | 4 | | | | | | | | | | |
| | L Pattinama Kerkhove | 6$^3$ | 6 | 4 | Q | U Radwańska | 6 | 6 | | | | | | | | | | |
| Q | U Radwańska | 7$^7$ | 2 | 6 | | | | | | Q | U Radwańska | 6 | 6 | | | | | |
| Q | S Djoubri | 3 | 1 | | | | | | | | L Küng | 4 | 1 | | | | | |
| | C Bucșa | 6 | 6 | | | C Bucșa | 1 | 4 | | | | | | | | | | |
| | L Küng | 6 | 7 | | | L Küng | 6 | 6 | | | | | | | | | | |
| 6 | T Korpatsch | 2 | 5 | | | | | | | | | | | | Q | U Radwańska | 3 | 1 |
| 3 | S Vögele | 6 | 5 | 6 | | | | | | | | | | | | J Cristian | 6 | 6 |
| Q | D Marcinkēviča | 4 | 7 | 2 | 3 | S Vögele | 6$^6$ | 2 | | | | | | | | | | |
| | LI Paar | 6 | 6 | | | LI Paar | 7$^8$ | 6 | | | | | | | | | | |
| | Ç Büyükakçay | 3 | 4 | | | | | | | | LI Paar | 6 | 2 | 1 | | | | |
| | J Cristian | 5 | 6 | 6 | | | | | | | J Cristian | 1 | 6 | 6 | | | | |
| WC | D Parry | 7 | 4 | 2 | | J Cristian | 2 | 7$^7$ | 6 | | | | | | | | | |
| WC | E Jacquemot | 4 | 6$^0$ | | 8 | C Tauson | 6 | 6$^4$ | 3 | | | | | | | | | |
| 8 | C Tauson | 6 | 7$^7$ | | | | | | | | | | | | | | | |

### 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 |
| 5 | T Martincová | 5 | 6 | 6 | | | | | | | | | | | | | |
| Q | F Di Sarra | 7 | 4 | 0 | 5 | T Martincová | 4 | 6$^7$ | | | | | | | | | |
| Q | G Desperrier | 3 | 1 | | WC | H Tan | 6 | 7$^9$ | | | | | | | | | |
| WC | H Tan | 6 | 6 | | | | | | | WC | H Tan | 6 | 6 | | | | |
| PR | Jia Lu | 6$^5$ | 4 | | | | | | | 4 | K Zavatska | 0 | 1 | | | | |
| JE | V Jiménez Kasintseva | 7$^7$ | 6 | | JE | V Jiménez Kasintseva | 1 | 6 | 2 | | | | | | | | |
| | G Gatto-Monticone | 4 | 1 | | 4 | K Zavatska | 6 | 3 | 6 | | | | | | | | |
| 4 | K Zavatska | 6 | 6 | | | | | | | | | | | WC | H Tan | 6 | 6 |
| 7 | V Tomova | 6 | 6 | | | | | | | | | | | Q | K von Deichmann | 1 | 0 |
| WC | A Hesse | 3 | 2 | | 7 | V Tomova | 0 | 4 | | | | | | | | | |
| Q | K von Deichmann | 6 | 6 | | Q | K von Deichmann | 6 | 6 | | | | | | | | | |
| | X You | 4 | 4 | | | | | | | Q | K von Deichmann | 7 | 6 | | | | |
| | M Di Giuseppe | 4 | 4 | | | | | | | 2 | A-L Friedsam | 5 | 4 | | | | |
| Q | R Šramková | 6 | 6 | | Q | R Šramková | 3 | 1 | | | | | | | | | |
| | I de Vroome | 3 | 7 | 2 | 2 | A-L Friedsam | 6 | 6 | | | | | | | | | |
| 2 | A-L Friedsam | 6 | 5 | 6 | | | | | | | | | | | | | |