2021 Qatar ExxonMobil Open – Singles
| Singles | |
|---|---|
| 2021 Qatar ExxonMobil Open | |
| Champion | Nikoloz Basilashvili |
| Runner-up | Roberto Bautista Agut |
| Score | 7–6(7–5), 6–2 |
| Draw | 28 (4 Q / 3 WC ) |
| Seeds | 8 |
Nikoloz Basilashvili defeated Roberto Bautista Agut in the final, 7–6(7–5), 6–2 to win the men's singles tennis title at the 2021 Qatar Open. Basilashvili saved a match point against Roger Federer in the quarterfinals.
Andrey Rublev was the defending champion, but lost in the semifinals to Bautista Agut. Rublev's run to the semifinals was notable for his not hitting a single ball, having received a bye in the first round and walkovers in both the second round and quarterfinals.
This tournament marked the return of former world No. 1 Federer to the tour for the first time since the 2020 Australian Open, due to a pair of knee surgeries since then. His defeat to Basilashvili marked a record-extending 24th and final loss from match point up in his career.