| Champ: |  Bianca Andreescu |
| Runner: |  Serena Williams |
| Score: | 3–1 ret. |
| Draw: | 56 (12 / 3) |
| Seeds: | 16 |
| Before Name: | Rogers Cup – Women's singles |
| After Name: | National Bank Open – Women's singles |
| After Year: | 2021 |
See main article: 2019 Rogers Cup.
Bianca Andreescu won the women's singles tennis title at the 2019 Canadian Open after Serena Williams retired in the final due to back spasms, with the scoreline at 3–1. Andreescu became the first Canadian to win the event since Faye Urban in 1969.[1]
Simona Halep was the defending champion, but retired in the quarterfinals against Marie Bouzková.
Naomi Osaka regained the WTA No. 1 singles ranking after Ashleigh Barty lost in the second round and Karolína Plíšková lost in the quarterfinals to Andreescu.
The top eight seeds received a bye into the second round.
