# 2021 Engie Open Nantes Atlantique – Singles

Cristina Bucșa was the defending champion but withdrew from the tournament.
Anhelina Kalinina won the title after Océane Dodin retired in the final at 7–6$^{(7–4)}$, 1–0.

## Seeds

* Anhelina Kalinina (champion)
* Varvara Gracheva (quarterfinals)
* Océane Dodin (final, retired)
* Martina Trevisan (semifinals)
* Kamilla Rakhimova (second round)
* Polona Hercog (first round)
* Vitalia Diatchenko (semifinals)
* Zheng Qinwen (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 | Final | Final | Final | Final |
| 1 | Anhelina Kalinina | 7$^7$ | 7$^8$ | | | | |
| 4 | Martina Trevisan | 6$^3$ | 6$^6$ | | | | |
| 4 | Martina Trevisan | 6$^3$ | 6$^6$ | 1 | Anhelina Kalinina | 7$^7$ | 1 |
| | | | | 3 | Océane Dodin | 6$^4$ | 0$^r$ |
| 3 | Océane Dodin | 6 | 6 | 3 | Océane Dodin | 6$^4$ | 0$^r$ |
| 7 | Vitalia Diatchenko | 2 | 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 | A Kalinina | 6 | 6 | | | | | | | | | | | | | | | |
| PR | K Thandi | 3 | 3 | | 1 | A Kalinina | 6 | 6 | | | | | | | | | | |
| Q | E Andreeva | 7$^7$ | 6 | | Q | E Andreeva | 2 | 4 | | | | | | | | | | |
| WC | C Monnet | 6$^5$ | 3 | | | | | | | 1 | A Kalinina | 6 | 6 | | | | | |
| Q | R Șerban | 6 | 6$^5$ | 4 | | | | | | Q | SB Grey | 0 | 4 | | | | | |
| Q | SB Grey | 4 | 7$^7$ | 6 | Q | SB Grey | 6 | 6 | | | | | | | | | | |
| | S Murray Sharan | 4 | 0$^r$ | | 5 | K Rakhimova | 1 | 2 | | | | | | | | | | |
| 5 | K Rakhimova | 6 | 0 | | | | | | | | | | | | 1 | A Kalinina | 7$^7$ | 7$^8$ |
| 4 | M Trevisan | 6 | 6 | | | | | | | | | | | | 4 | M Trevisan | 6$^3$ | 6$^6$ |
| Q | S Cakarevic | 0 | 3 | | 4 | M Trevisan | 7$^7$ | 6 | | | | | | | | | | |
| | D Snigur | 6 | 4 | | | D Snigur | 6$^4$ | 4 | | | | | | | | | | |
| SE | S Waltert | 3 | 1$^r$ | | | | | | | 4 | M Trevisan | 6 | 3 | 6 | | | | |
| Q | İ Soylu | 1$^r$ | | | | | | | | WC | A Robbe | 3 | 6 | 1 | | | | |
| WC | A Robbe | 2 | | | WC | A Robbe | 6 | 3 | 6 | | | | | | | | | |
| WC | A Albié | 7 | 6 | | WC | A Albié | 4 | 6 | 3 | | | | | | | | | |
| 8 | Q Zheng | 5 | 3 | | | | | | | | | | | | | | | |

### 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 |
| 6 | P Hercog | 3 | 4 | | | | | | | | | | | | | | | |
| | U Radwańska | 6 | 6 | | | U Radwańska | 3 | 4 | | | | | | | | | | |
| | J Ponchet | 2 | 4 | | | L Pattinama Kerkhove | 6 | 6 | | | | | | | | | | |
| | L Pattinama Kerkhove | 6 | 6 | | | | | | | | L Pattinama Kerkhove | 6$^6$ | 3 | | | | | |
| LL | E Yashina | 2 | 5 | | | | | | | 3 | O Dodin | 7$^8$ | 6 | | | | | |
| WC | M Noël | 6 | 7 | | WC | M Noël | 6$^6$ | 6 | 5 | | | | | | | | | |
| | C Paquet | 4 | 7$^7$ | 6$^4$ | 3 | O Dodin | 7$^8$ | 4 | 7 | | | | | | | | | |
| 3 | O Dodin | 6 | 6$^2$ | 7$^7$ | | | | | | | | | | | 3 | O Dodin | 6 | 6 |
| 7 | V Diatchenko | 6 | 6 | | | | | | | | | | | | 7 | V Diatchenko | 2 | 3 |
| | S Mendez | 4 | 2 | | 7 | V Diatchenko | 7 | 4 | 6 | | | | | | | | | |
| | A Raina | 6 | 1 | 2 | Q | S Nahimana | 5 | 6 | 1 | | | | | | | | | |
| Q | S Nahimana | 4 | 6 | 6 | | | | | | 7 | V Diatchenko | 6 | 3 | 6 | | | | |
| LL | D Marcinkēviča | 0 | 5 | | | | | | | 2 | V Gracheva | 1 | 6 | 3 | | | | |
| Q | D Vismane | 6 | 7 | | Q | D Vismane | 6 | 5 | 4 | | | | | | | | | |
| Q | E Bektas | 5 | 5 | | 2 | V Gracheva | 4 | 7 | 6 | | | | | | | | | |
| 2 | V Gracheva | 7 | 7 | | | | | | | | | | | | | | | |