2005 Western & Southern Financial Group Women's Open – Singles

Lindsay Davenport was the defending champion, but decided not to participate that year.

Patty Schnyder won the title, defeating Akiko Morigami 6–4, 6–0 in the final.

Seeds
• # Patty Schnyder (champion)

• #🇷🇺 Vera Zvonareva (second round)

• # Jelena Janković (quarterfinals)

• #🇸🇰 Daniela Hantuchová (semifinals)

• #🇫🇷 Marion Bartoli (first round)

• #🇯🇵 Ai Sugiyama (second round)

• #🇩🇪 Anna-Lena Grönefeld (first round)

• #🇨🇿 Květa Peschke (first round)