2021 National Bank Open – Women's singles

Camila Giorgi defeated Karolína Plíšková in the final, 6–3, 7–5 to win the women's singles tennis title at the 2021 Canadian Open. It was her third career WTA Tour title, her first at the WTA 1000 level, and her first since Linz in 2018.

Bianca Andreescu was the defending champion from when the event was last held in 2019, but lost in the third round to Ons Jabeur.

Seeds
The top eight seeds received a bye into the second round. • 🇧🇾 Aryna Sabalenka (semifinals)

• 🇨🇦 Bianca Andreescu (third round)

• 🇺🇦 Elina Svitolina (second round)

• 🇨🇿 Karolína Plíšková (final)

• 🇪🇸 Garbiñe Muguruza (second round)

• 🇷🇴 Simona Halep (second round)

• 🇨🇿 Petra Kvitová (third round)

• 🇧🇾 Victoria Azarenka (quarterfinals)

• 🇧🇪 Elise Mertens (first round)

• 🇷🇺 Anastasia Pavlyuchenkova (second round)

• Maria Sakkari (third round)

• 🇰🇿 Elena Rybakina (first round)

• 🇹🇳 Ons Jabeur (quarterfinals)

• 🇨🇿 Karolína Muchová (first round)

• 🇺🇸 Coco Gauff (quarterfinals)

• 🇺🇸 Madison Keys (first round)

Seeds
• # 🇧🇪 Alison Van Uytvanck (qualified)

• # 🇫🇷 Kristina Mladenovic (qualifying competition)

• # 🇨🇿 Tereza Martincová (qualified)

• # 🇬🇧 Heather Watson (qualifying competition)

• # 🇺🇸 Ann Li (qualifying competition)

• # 🇫🇷 Caroline Garcia (qualified)

• # 🇺🇸 Amanda Anisimova (qualified)

• # 🇺🇸 Bernarda Pera (first round)

• # Polona Hercog (qualifying competition)

• # 🇷🇺 Anastasia Potapova (qualified)

• # 🇫🇷 Clara Burel (qualified)

• # 🇺🇸 Christina McHale (qualifying competition)

• # 🇫🇷 Océane Dodin (qualified)

• # 🇦🇺 Astra Sharma (first round)

• # 🇺🇸 Kristie Ahn (qualifying competition)

• # 🇷🇺 Kamilla Rakhimova (qualifying competition)

Qualifiers
• # 🇧🇪 Alison Van Uytvanck

• # 🇷🇺 Anastasia Potapova

• # 🇨🇿 Tereza Martincová

• # 🇫🇷 Clara Burel

• # 🇫🇷 Océane Dodin

• # 🇫🇷 Caroline Garcia

• # 🇺🇸 Amanda Anisimova

• # 🇬🇧 Harriet Dart