| Champ: |  Dominic Thiem |
| Runner: | João Sousa |
| Score: | 6–4, 6–1 |
| Draw: | 28 (4 / 3) |
| Seeds: | 8 |
| Type: | singles doubles |
See main article: 2015 Croatia Open Umag. Pablo Cuevas was the last edition champion, but he chose to defend another of his previous title in Båstad which was held simultaneously with the Croatia Open Umag this year.
Dominic Thiem won the title, defeating João Sousa in the final, 6–4, 6–1.
The top four seeds receive a bye into the second round.