2021 Astana Open – Men's singles
| Men's singles | |
|---|---|
| 2021 Astana Open | |
| Champion | Kwon Soon-woo |
| Runner-up | James Duckworth |
| Score | 7–6(8–6), 6–3 |
John Millman was the defending champion, 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.