2011 Heineken Open – Singles

John Isner was the defending champion but lost in the quarterfinals to David Nalbandian. David Ferrer won the title, defeating Nalbandian 6–3, 6–2 in the final.

Seeds
The top four seeds receive a bye to the second round. • # 🇪🇸 David Ferrer (champion)

• # 🇪🇸 Nicolás Almagro (semifinals)

• # 🇺🇸 John Isner (quarterfinals)

• # 🇪🇸 Albert Montañés (second round)

• # 🇦🇷 Juan Mónaco (first round)

• # 🇦🇷 David Nalbandian (final)

• # 🇧🇷 Thomaz Bellucci (quarterfinals)

• # 🇩🇪 Philipp Kohlschreiber (quarterfinals)