2021 Western & Southern Open – Women's singles
| Women's singles | |
|---|---|
| 2021 Western & Southern Open | |
| Champion | Ashleigh Barty |
| Runner-up | Jil Teichmann |
| Score | 6–3, 6–1 |
| Draw | 56 (8 Q / 5 WC ) |
| Seeds | 16 |
Ashleigh Barty defeated Jil Teichmann in the final, 6–3, 6–1 to win the women's singles tennis title at the 2021 Cincinnati Masters. Barty did not drop a set en route to her first Cincinnati Masters title. It was her fifth and last title of the season, her third WTA 1000 title, and her 13th career WTA Tour singles title.
Victoria Azarenka was the defending champion, but lost in the third round to Barty.
Angelique Kerber contested her 1000th match in her professional career in the quarterfinals against Petra Kvitová; she won the match after Kvitová retired.
This was the final tournament in which former world No. 4 and British No. 1 Johanna Konta competed before her retirement. She was defeated in the first round by Karolína Muchová.