2011 Western & Southern Open – Women's singles

Maria Sharapova defeated Jelena Janković in the final, 4–6, 7–6(7–3), 6–3 to win the women's singles tennis title at the 2011 Cincinnati Masters.

Kim Clijsters was the reigning champion, but withdrew due to an abdominal injury.

Seeds
The top eight seeds received a bye into the second round. • # Caroline Wozniacki (second round)

• # 🇷🇺 Vera Zvonareva (semifinals)

• # 🇧🇾 Victoria Azarenka (withdrew due to a right hand injury)

• # 🇷🇺 Maria Sharapova (champion)

• # 🇨🇳 Li Na (third round)

• # 🇨🇿 Petra Kvitová (third round)

• # 🇮🇹 Francesca Schiavone (third round)

• # 🇫🇷 Marion Bartoli (third round)

• # 🇩🇪 Andrea Petkovic (semifinals)

• # 🇦🇺 Samantha Stosur (quarterfinals)

• # 🇵🇱 Agnieszka Radwańska (withdrew due to a right shoulder injury)

• # 🇷🇺 Anastasia Pavlyuchenkova (first round)

• # 🇷🇸 Jelena Janković (final)

• # 🇷🇺 Svetlana Kuznetsova (third round)

• # 🇷🇸 Ana Ivanovic (second round)

• # 🇨🇳 Peng Shuai (quarterfinals, withdrew due to a left hip injury)

• # 🇧🇪 Yanina Wickmayer (second round)