| Champ: |  Kwon Soon-woo |
| Runner: |  James Duckworth |
| Score: | 7–6(8–6), 6–3 |
| Main Name: | Astana Open |
| After Name: | Astana Open – Singles |
See main article: article and 2021 Astana Open.
John Millman was the defending champion,[1] but lost in the quarterfinals to James Duckworth.
Kwon Soon-woo won his first ATP Tour title, defeating Duckworth in the final, 7–6(8–6), 6–3. Kwon became the first South Korean player to win a title at ATP Tour level since Lee Hyung-taik in the 2003 Sydney tournament.
The top four seeds received a bye into the second round.