| Men's singles | |
|---|---|
| 2018 President's Cup (tennis) | |
| Champion |  Sebastian Ofner |
| Runner-up |  Daniel Brands |
| Final score | 7–6(7–5), 6–3 |
Egor Gerasimov was the defending champion but lost in the second round to Jurij Rodionov.
Sebastian Ofner won the title after defeating Daniel Brands 7–6(7–5), 6–3 in the final.
Mikhail Youzhny (second round)
Alexander Bublik (first round) Sebastian Ofner (champion)
Hiroki Moriya (first round)
Egor Gerasimov (second round)
Lee Duck-hee (second round) Ivan Nedelko (first round)
Cem İlkel (first round)| Semifinals | Final | ||||||||||||
| Daniel Brands | 6 | 3 | 7 | ||||||||||
| Jurij Rodionov | 4 | 6 | 5 | ||||||||||
| Daniel Brands | 65 | 3 | |||||||||||
| 3 | Sebastian Ofner | 77 | 6 | ||||||||||
| 3 | Sebastian Ofner | 6 | 6 | ||||||||||
 Alexei Popyrin | 3 | 3 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | M Youzhny | 6 | 2 | 7 | |||||||||||||||||||||||
 A González | 3 | 6 | 5 | 1 | M Youzhny | 6 | 4 | 3 | |||||||||||||||||||
| Q |  S Myneni | 77 | 4 | 6 | Q | S Myneni | 3 | 6 | 6 | ||||||||||||||||||
 A Šetkić | 65 | 6 | 4 | Q | S Myneni | 4 | 712 | 5 | |||||||||||||||||||
| Hiroyasu Ehara | 3 | 65 | D Brands | 6 | 610 | 7 | |||||||||||||||||||||
| I Gakhov | 6 | 77 | I Gakhov | 77 | 3 | 3 | |||||||||||||||||||||
| D Brands | 6 | 6 | D Brands | 63 | 6 | 6 | |||||||||||||||||||||
| 8 | C İlkel | 0 | 4 | D Brands | 6 | 3 | 7 | ||||||||||||||||||||
| 4 | H Moriya | 4 | 2 | J Rodionov | 4 | 6 | 5 | ||||||||||||||||||||
 M Janvier | 6 | 6 | M Janvier | 4 | 7 | 6 | |||||||||||||||||||||
| D Yevseyev | 4 | 6 | 6 | D Yevseyev | 6 | 5 | 3 | ||||||||||||||||||||
| R Safiullin | 6 | 3 | 4 | M Janvier | 77 | 4 | 4 | ||||||||||||||||||||
 Y Mertens | 5 | 0 | J Rodionov | 63 | 6 | 6 | |||||||||||||||||||||
| J Rodionov | 7 | 6 | J Rodionov | 7 | 6 | ||||||||||||||||||||||
| D Guez | 66 | 3 | 5 | E Gerasimov | 5 | 2 | |||||||||||||||||||||
| 5 | E Gerasimov | 78 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 7 | I Nedelko | 62 | 7 | 3 | |||||||||||||||||||||||
| WC | A Nedovyesov | 77 | 5 | 6 | WC | A Nedovyesov | 6 | 64 | 6 | ||||||||||||||||||
| LL | A Kadhe | 6 | 3 | LL | A Kadhe | 3 | 77 | 4 | |||||||||||||||||||
| LL | D Zhyrmont | 2 | 3r | WC | A Nedovyesov | 5 | 6 | 1 | |||||||||||||||||||
| WC |  F Dustov | 4 | 2 | 3 | S Ofner | 7 | 1 | 6 | |||||||||||||||||||
| Q | K Sultanov | 6 | 6 | Q | K Sultanov | 3 | 3 | ||||||||||||||||||||
| WC | T Khabibulin | 5 | 1 | 3 | S Ofner | 6 | 6 | ||||||||||||||||||||
| 3 | S Ofner | 7 | 6 | 3 | S Ofner | 6 | 6 | ||||||||||||||||||||
| 6 | D-h Lee | 6 | 6 | A Popyrin | 3 | 3 | |||||||||||||||||||||
| WC | Sagadat Ayap | 4 | 2 | 6 | D-h Lee | 7 | 64 | 5 | |||||||||||||||||||
 R Ortega Olmedo | 68 | 6 | 5 | Q | P Kotov | 5 | 77 | 7 | |||||||||||||||||||
| Q | P Kotov | 710 | 4 | 7 | Q | P Kotov | 1 | 4 | |||||||||||||||||||
| Y Jankovits | 6 | 77 | A Popyrin | 6 | 6 | ||||||||||||||||||||||
| Q | H Grenier | 3 | 64 | Y Jankovits | 66 | 5 | |||||||||||||||||||||
| A Popyrin | 5 | 6 | 6 | A Popyrin | 78 | 7 | |||||||||||||||||||||
| 2 | A Bublik | 7 | 3 | 4 | |||||||||||||||||||||||
Richard Gasquet was the defending champion but withdrew before the tournament began.
Pablo Cuevas was the three-time defending champion, but lost in the semifinals to Fabio Fognini.
Marin Čilić was the defending champion, but lost in the second round to Malek Jaziri.
Egor Gerasimov was the defending champion and successfully defended his title.
Damir Džumhur was the defending champion, but lost to Egor Gerasimov in the first round.
Karen Khachanov was the defending champion, but withdrew before the tournament began.
Steve Johnson was the two-time defending champion, but lost in the second round to Daniel Elahi Galán.
Marco Cecchinato was the defending champion, but withdrew due to illness.
Sebastian Ofner was the defending champion but lost in the third round to Aleksandar Vukic.
Dominic Thiem was the defending champion, but chose to compete in the Laver Cup instead.
Karen Khachanov was the defending champion, but lost in the quarterfinals to Andreas Seppi.
Stefanos Tsitsipas was the defending champion and successfully defended his title, defeating Félix Auger-Aliassime in the final, 6–3, 6–4.
Feliciano López was the defending champion from when the event was last held in 2019, but lost in the second round to Denis Shapovalov.
Kevin Anderson defeated Jenson Brooksby in the final, 7–6(10–8), 6–4, to win the men's singles tennis title at the 2021 Hall of Fame Open. It was played on outdoor grass courts and was part of the 250 series of the 2021 ATP Tour. It took place at the International Tennis Hall of Fame in Newport, Rhode Island, United States from 12–18 July 2021.
Alex de Minaur was the reigning champion from when the tournament was last held in 2019, but chose not to participate this year.
Jannik Sinner was the defending champion and successfully defended his title, defeating Gaël Monfils in the final, 6–3, 6–4.
Andrey Rublev was the reigning champion from when the tournament was last held in 2019, but lost to Adrian Mannarino in the second round in a rematch of the 2019 final.
Andrey Rublev was the defending champion, but lost in the quarterfinals to Botic van de Zandschulp.
Tommy Paul defeated the defending champion, Denis Shapovalov, in the final, 6–4, 2–6, 6–4, to win the singles title at the 2021 Stockholm Open. This was Paul's first ATP Tour title.
Félix Auger-Aliassime defeated Stefanos Tsitsipas in the final, 6–4, 6–2 to win the singles title at the 2022 Rotterdam Open. It was his maiden ATP Tour title, following eight runner-up finishes in prior finals. Tsitsipas fell to 0–8 in ATP Tour 500 finals.