2011 Swiss Indoors – Singles

Roger Federer was the defending champion and retained the title, beating Kei Nishikori in the final, 6–1, 6–3. It was Federer's first title in almost ten months but was the first of three that Federer won in succession to end the season.

Seeds
• # 🇷🇸 Novak Djokovic (semifinals)

• # 🇬🇧 Andy Murray (withdrew due to right gluteal strain)

• # Roger Federer (champion)

• # 🇨🇿 Tomáš Berdych (first round)

• # 🇺🇸 Mardy Fish (first round, retired due to left hamstring injury)

• # 🇷🇸 Janko Tipsarević (first round, retired due to left hamstring injury)

• # 🇺🇸 Andy Roddick (quarterfinals)

• # 🇷🇸 Viktor Troicki (first round)

Seeds
• # 🇦🇺 Bernard Tomic (first round)

• # 🇺🇸 James Blake (qualified)

• # 🇵🇱 Łukasz Kubot (qualified)

• # 🇺🇦 Sergiy Stakhovsky (first round)

• # 🇰🇿 Mikhail Kukushkin (qualifying competition, lucky loser)

• # 🇺🇿 Denis Istomin (first round)

• # 🇺🇸 Ryan Harrison (first round)

• # 🇩🇪 Michael Berrer (first round)

Qualifiers
• # Michael Lammer

• # 🇺🇸 James Blake

• # 🇵🇱 Łukasz Kubot

• # 🇩🇪 Tobias Kamke

Lucky losers

 * 1) 🇰🇿 Mikhail Kukushkin
 * 2)  Marco Chiudinelli