2013 Portugal Open – Men's singles

Juan Martín del Potro was the defending champion, but withdrew before the tournament, because of illness. Stanislas Wawrinka defeated David Ferrer 6–1, 6–4 in the final to win the title.

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

• # Stanislas Wawrinka (champion)

• # 🇮🇹 Andreas Seppi (semifinals)

• # 🇮🇹 Fabio Fognini (quarterfinals)

• # 🇫🇷 Julien Benneteau (first round)

• # 🇫🇷 Benoît Paire (second round)

• # 🇦🇷 Horacio Zeballos (first round)

• # 🇪🇸 Tommy Robredo (quarterfinals)

Seeds
• # Robin Haase (qualified)

• # Thiemo de Bakker (qualifying competition)

• # 🇪🇸 Javier Martí (qualifying competition)

• # 🇧🇪 Niels Desein (qualified)

• # 🇷🇺 Igor Andreev (first round)

• # 🇪🇸 Pablo Carreño (qualified)

• # Henri Laaksonen (qualifying competition)

• # Frederico Gil (second round)

Qualifiers
• # Robin Haase

• # Rui Machado

• # 🇪🇸 Pablo Carreño

• # 🇧🇪 Niels Desein