| Champ: |  Casper Ruud |
| Runner: |  Federico Coria |
| Score: | 6–3, 6–3 |
| Draw: | 28 (4 / 3) |
| Seeds: | 8 |
| Main Name: | Swedish Open |
| Before Year: | 2019 |
| Before Name: | Swedish Open – Men's singles |
See main article: article and 2021 Swedish Open.
Nicolás Jarry was the reigning champion from when the tournament was last held in 2019, but chose to not defend his title.
Casper Ruud won the title, defeating Federico Coria in the final, 6–3, 6–3.
The top four seeds receive a bye into the second round.