| Champ: |  Madison Keys |
| Runner: |  Svetlana Kuznetsova |
| Score: | 7–5, 7–6(7–5) |
| Draw: | 56 (12 / 5) |
| Seeds: | 16 |
Madison Keys defeated Svetlana Kuznetsova in the final, 7–5, 7–6(7–5) to win the women's singles tennis title at the 2019 Cincinnati Masters.
Kiki Bertens was the defending champion, but lost in the second round to Venus Williams.
Naomi Osaka retained the world No. 1 singles ranking after the tournament. Ashleigh Barty and Karolína Plíšková were also in contention for the top ranking.[1]
This tournament marked Maria Sharapova's final WTA Tour-level victory before her retirement; she defeated Alison Riske in the first round before losing to Barty in the second round.
The top eight seeds received a bye into the second round.