| Champ: |  Aslan Karatsev |
| Runner: | Lloyd Harris |
| Score: | 6–3, 6–2 |
| Draw: | 48 (6 / 4) |
| Seeds: | 16 |
See main article: 2021 Dubai Tennis Championships.
Aslan Karatsev won his first ATP Tour singles title, defeating Lloyd Harris in the final, 6–3, 6–2 to win the men's singles tennis title at the 2021 Dubai Tennis Championships. Karatsev became the second wildcard in the tournament's history to win the men's singles title. Harris was the first qualifier to reach the final of the Dubai Tennis Championships.
Novak Djokovic was the defending champion, but chose not to participate.[1]
All seeds receive a bye into the second round.
The players who also received a bye into the second round were as follows, each semifinalist from Doha or Marseille:
The other six byes were removed, and six players were added to the main draw.
