2021 Erste Bank Open – Singles
| Singles | |
|---|---|
| 2021 Erste Bank Open | |
| Champion | Alexander Zverev |
| Runner-up | Frances Tiafoe |
| Score | 7–5, 6–4 |
| Draw | 32 (4 Q / 3 WC ) |
| Seeds | 8 |
Andrey Rublev was the defending champion, but chose to compete in St. Petersburg instead.
Alexander Zverev won the title, defeating Frances Tiafoe in the final, 7–5, 6–4.