The 2021 Chicago Women's Open was a tennis tournament held in Chicago, Illinois for female professional tennis players, and part of the 2021 WTA Tour.[1] It was played on outdoor hard courts in the week prior to the 2021 U.S. Open. This marked the first time since 1997 that a WTA tournament was held in Chicago.[2]
See main article: 2021 Chicago Women's Open – Singles.
Elina Svitolina def. 
Alizé Cornet, 7–5, 6–4.This was Svitolina's sixteenth WTA Tour singles title, and first of the year.
See main article: 2021 Chicago Women's Open – Doubles.
Nadiia Kichenok / 
Raluca Olaru def. Lyudmyla Kichenok / 
Makoto Ninomiya, 7–6(8–6), 5–7, [10–8].| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Ukraine | Elina Svitolina | 6 | 1 | |
 Italy | ||||
| Romania | Sorana Cîrstea | 38 | 3 | |
| Tamara Zidanšek | 40 | 4 | ||
 Czech Republic | Markéta Vondroušová | 41 | 5 | |
| Viktorija Golubic | 47 | 6 | ||
| France | Kristina Mladenovic | 54 | 7 | |
| Ukraine | Marta Kostyuk | 56 | 8 | |
| France | Alizé Cornet | 57 | 9 |
The following players received wildcards into the main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Camila Giorgi → replaced by Clara Burel
Varvara Gracheva
Elena Rybakina → replaced by Misaki Doi
Ajla Tomljanović → replaced by Fiona Ferro| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 United States | Nicole Melichar | Demi Schuurs | 23 | 1 | ||
| Chan Hao-ching | Latisha Chan | 42 | 2 | |||
| Ukraine | Nadiia Kichenok | Romania | Raluca Olaru | 80 | 3 | |
| Ukraine | Lyudmyla Kichenok | Japan | Makoto Ninomiya | 100 | 4 |
Anastasia Potapova / 
Heather Watson → replaced by Bárbara Gatica / 
Rebeca Pereira