| Champ: | Marin Čilić |
| Runner: |  Roberto Bautista Agut |
| Score: | 6–4, 6–4 |
| Draw: | 28 (4 / 3) |
| Seeds: | 8 |
| Before Name: | Kremlin Cup – Men's singles |
| After Name: | Kremlin Cup – Men's singles |
See main article: 2015 Kremlin Cup.
Defending champion Marin Čilić defeated Roberto Bautista Agut in the final, 6–4, 6–4 to win the men's singles tennis title at the 2015 Kremlin Cup.
The top four seeds received a bye into the second round.