The 2021 Geneva Open (sponsored by Gonet) was a men's tennis tournament played on outdoor clay courts. It was the 18th edition of the Geneva Open and part of the ATP Tour 250 series of the 2021 ATP Tour. It took place at the Tennis Club de Genève in Geneva, Switzerland, from May 15 through May 22, 2021.[1]
See main article: 2021 Geneva Open – Singles.
Casper Ruud def. 
Denis Shapovalov, 7–6(8–6), 6–4See main article: 2021 Geneva Open – Doubles.
John Peers / 
Michael Venus def. 
Simone Bolelli / 
Máximo González, 6–2, 7–5| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q | width=85 | Q2 | width=85 | Q1 |
| Singles | 250 | 150 | 90 | 45 | 20 | 0 | 12 | 6 | 0 | |||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Doubles | 0 |
| Event | W | F | SF | QF | Round of 16 | Round of 32 | width=85 | Q2 | width=85 | Q1 |
| Singles | €41,145 | €29,500 | €21,000 | €14,000 | €9,000 | €5,415 | €2,645 | €1,375 | ||
| Doubles* | €15,360 | €11,000 | €7,250 | €4,710 | €2,760 |
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
| Roger Federer[2] | 8 | 1 | ||
| Canada | Denis Shapovalov | 14 | 2 | |
| Norway | Casper Ruud | 16 | 3 | |
| Grigor Dimitrov | 17 | 4 | ||
| Italy | Fabio Fognini | 28 | 6 | |
 France | Benoît Paire | 35 | 7 | |
| France | Adrian Mannarino | 36 | 8 |
The following players received wildcards into the singles main draw:
The following players received entry from the qualifying draw:
The following player received entry as a lucky loser:
Alexander Bublik → replaced by 
Tennys Sandgren
Feliciano López Alejandro Davidovich Fokina → replaced by 
Thiago Monteiro Alex de Minaur → replaced by Jordan Thompson
Filip Krajinović → replaced by Salvatore Caruso Fernando Verdasco| Country | Player | Country | Player | Rank1 | Seed | |
|---|---|---|---|---|---|---|
 Austria | Oliver Marach | Mate Pavić | 31 | 1 | ||
| Australia | John Peers | New Zealand | Michael Venus | 42 | 2 | |
| Raven Klaasen |  Japan | Ben McLachlan | 65 | 3 | ||
 India | Rohan Bopanna | Franko Škugor | 73 | 4 |
The following pairs received wildcards into the doubles main draw:
Alex de Minaur / Jordan Thompson → replaced by Nathaniel Lammons / Jackson Withrow Andrey Golubev Nicholas Monroe / Reilly Opelka → replaced by Nicholas Monroe / Benoît Paire Rajeev Ram / 
Joe Salisbury → replaced by Pablo Cuevas / Guido Pella
