2011 Gerry Weber Open – Singles

Lleyton Hewitt was the defending champion, but lost to Philipp Kohlschreiber in the quarterfinals.

Kohlschreiber won the tournament, defeating Philipp Petzschner in an all-German final, the first in the tournament's history, after Petzschner retired in the second set at a score of 7–6, 2–0.

Seeds
• # Roger Federer (withdrew due to groin injury)

• # 🇨🇿 Tomáš Berdych (semifinals)

• # 🇫🇷 Gaël Monfils (semifinals)

• # 🇷🇺 Mikhail Youzhny (withdrew due to left foot injury)

• # 🇷🇸 Viktor Troicki (quarterfinals)

• # 🇩🇪 Florian Mayer (quarterfinals)

• # 🇺🇦 Alexandr Dolgopolov (second round)

• # 🇨🇦 Milos Raonic (quarterfinals)