The 2011 Concurso Internacional de Tenis – San Sebastián was a professional tennis tournament played on clay courts. It was the fourth edition of the tournament which is part of the 2011 ATP Challenger Tour. It took place in San Sebastián, Spain between 15 and 21 August 2011.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Spain | Albert Ramos | 72 | 1 | |
| Spain | Pere Riba | 75 | 2 | |
| Spain | Daniel Gimeno Traver | 94 | 3 | |
| Thiemo de Bakker | 107 | 4 | ||
 France | Benoît Paire | 119 | 5 | |
| France | Augustin Gensse | 147 | 6 | |
| Spain | Guillermo Olaso | 167 | 7 | |
| Spain | Roberto Bautista Agut | 182 | 8 |
The following players received wildcards into the singles main draw:
Albert Alcaraz Ivorra Iñigo Cervantes-Huegun Juan Lizariturry Gianni MinaThe following players received entry from the qualifying draw:
Gorka Fraile Carlos Gómez-Herrera Miguel Ángel López JaénSee main article: 2011 Concurso Internacional de Tenis – San Sebastián – Singles. Albert Ramos def. Pere Riba 6–1, 6–2
See main article: 2011 Concurso Internacional de Tenis – San Sebastián – Doubles. 
Stefano Ianni / Simone Vagnozzi def. Daniel Gimeno Traver / Israel Sevilla, 6–3, 6–4