| Champ: |  Tommy Robredo |
| Runner: |  Fabio Fognini |
| Score: | 6–0, 6–3 |
| Draw: | 28 (4 / 3) |
| Seeds: | 8 |
| Type: | singles doubles |
See main article: 2013 ATP Vegeta Croatia Open Umag. Marin Čilić was the defending champion, but withdrew with a knee injury before the tournament began.
Tommy Robredo won the title, defeating Fabio Fognini in the final, 6–0, 6–3.
The top four seeds receive a bye into the second round.