# 2021 Chicago Challenger – Singles

Petra Martić was the defending champion, but chose to compete at the 2021 Western & Southern Open instead.
Clara Tauson won the title, defeating wildcard Emma Raducanu in the final, 6–1, 2–6, 6–4.

## Seeds

* Alison Van Uytvanck (first round)
* Danka Kovinić (first round)
* Ann Li (semifinals)
* Anhelina Kalinina (first round)
* Madison Brengle (first round)
* Amanda Anisimova (second round, retired)
* Ana Konjuh (first round)
* Varvara Gracheva (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 | Semifinals | Final | Final | Final | Final | Final |
| WC | Emma Raducanu | 7$^7$ | 4 | 6 | | | | | |
| | Claire Liu | 6$^3$ | 6 | 1 | | | | | |
| | Claire Liu | 6$^3$ | 6 | 1 | WC | Emma Raducanu | 1 | 6 | 4 |
| | | | | | | Clara Tauson | 6 | 2 | 6 |
| 3 | Ann Li | 6$^5$ | 1 | | | Clara Tauson | 6 | 2 | 6 |
| | Clara Tauson | 7$^7$ | 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 | Semifinals |
| 1 | A Van Uytvanck | 6$^7$ | 3 | | | | | | | | | | | | | | | |
| WC | E Raducanu | 7$^9$ | 6 | | WC | E Raducanu | 6 | 7 | | | | | | | | | | |
| | C Burel | 7 | 3 | | | C Burel | 2 | 5 | | | | | | | | | | |
| PR | I Jorović | 5 | 2$^r$ | | | | | | | WC | E Raducanu | 7$^7$ | 0 | | | | | |
| | J Niemeier | 6 | 6 | | | | | | | | J Niemeier | 6$^4$ | 0$^r$ | | | | | |
| | G Minnen | 2 | 2 | | | J Niemeier | 3 | 6 | 4 | | | | | | | | | |
| | N Párrizas Díaz | 6 | 2 | 4 | 6 | A Anisimova | 6 | 3 | 0$^r$ | | | | | | | | | |
| 6 | A Anisimova | 3 | 6 | 6 | | | | | | | | | | WC | E Raducanu | 7$^7$ | 4 | 6 |
| 4 | A Kalinina | 2 | 4 | | | | | | | | | | | | C Liu | 6$^3$ | 6 | 1 |
| | A Kalinskaya | 6 | 6 | | A Kalinskaya | A Kalinskaya | 4 | 6 | 3 | | | | | | | | | |
| | C Liu | 6 | 6 | | C Liu | C Liu | 6 | 4 | 6 | | | | | | | | | |
| | Y Bonaventure | 3 | 2 | | | | | | | | C Liu | 6 | 6 | | | | | |
| PR | K Kozlova | 5 | 6 | 7$^7$ | | | | | | Q | V Diatchenko | 2 | 3 | | | | | |
| Q | M Zanevska | 7 | 4 | 6$^2$ | PR | K Kozlova | 5 | 6 | 4 | | | | | | | | | |
| Q | V Diatchenko | 7$^7$ | 6 | | Q | V Diatchenko | 7 | 1 | 6 | | | | | | | | | |
| 7 | A Konjuh | 6$^4$ | 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 |
| 5 | M Brengle | 7$^7$ | 6$^5$ | 4 | | | | | | | | | | | | | | |
| | Z Diyas | 6$^2$ | 7$^7$ | 6 | Z Diyas | Z Diyas | 6 | 1 | 6 | | | | | | | | | |
| | H Tan | 4 | 6 | 3 | S Errani | S Errani | 3 | 6 | 4 | | | | | | | | | |
| | S Errani | 6 | 2 | 6 | | | | | | | Z Diyas | 4 | 6 | 3 | | | | |
| WC | C Vandeweghe | 6$^3$ | 4 | | | | | | | 3 | A Li | 6 | 2 | 6 | | | | |
| | O Dodin | 7$^7$ | 6 | | | O Dodin | 3 | 1 | | | | | | | | | | |
| WC | W Osuigwe | 3 | 4 | | 3 | A Li | 6 | 6 | | | | | | | | | | |
| 3 | A Li | 6 | 6 | | | | | | | | | | | | 3 | A Li | 6$^5$ | 1 |
| 8 | V Gracheva | 4 | 6 | 6 | | | | | | | | | | | | C Tauson | 7$^7$ | 6 |
| | M Doi | 6 | 4 | 4 | 8 | V Gracheva | 7 | 3 | 4 | | | | | | | | | |
| Q | C Dolehide | 3 | 6 | 2 | | S Sanders | 5 | 6 | 6 | | | | | | | | | |
| | S Sanders | 6 | 4 | 6 | | | | | | S Sanders | S Sanders | 5 | 3 | | | | | |
| Q | H Dart | 1 | 7$^7$ | 2 | | | | | | C Tauson | C Tauson | 7 | 6 | | | | | |
| | C Tauson | 6 | 6$^2$ | 6 | | C Tauson | 6 | 3 | 6 | | | | | | | | | |
| WC | H Baptiste | 6 | 6 | | WC | H Baptiste | 2 | 6 | 3 | | | | | | | | | |
| 2 | D Kovinić | 3 | 4 | | | | | | | | | | | | | | | |

## Qualifying
### Seeds

* Kristína Kučová (qualifying competition)
* Maryna Zanevska (qualified)
* Harmony Tan (moved to main draw)
* Vitalia Diatchenko (qualified)

### Qualifiers

* Harriet Dart
* Maryna Zanevska
* Caroline Dolehide
* Vitalia Diatchenko

### Draw
#### First qualifier

| Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 1 | Kristína Kučová | 6 | 4 | 4 |
| Alt | Harriet Dart | 2 | 6 | 6 |

#### Second qualifier

| Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 2 | Maryna Zanevska | 6 | 6 | |
| | Dalma Gálfi | 2 | 2 | |

#### Third qualifier

| Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| Alt | Lesley Pattinama Kerkhove | 6 | 2 | 3 |
| WC | Caroline Dolehide | 2 | 6 | 6 |

#### Fourth qualifier

| Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition | Qualifying competition |
| 4 | Vitalia Diatchenko | 7$^7$ | 6 | |
| WC | Dalayna Hewitt | 6$^5$ | 3 | |