| Men's singles | |
|---|---|
| 2024 Keio Challenger | |
| Champion |  Yuta Shimizu |
| Runner-up |  Li Tu |
| Score | 6–7(4–7), 6–4, 6–2 |
Yosuke Watanuki was the defending champion [1] but chose not to defend his title.
Yuta Shimizu won the title after defeating Li Tu 6–7(4–7), 6–4, 6–2 in the final. [2]
Mattia Bellucci (first round) Yasutaka Uchiyama (first round)
Coleman Wong (quarterfinals) Alex Bolt (first round) Sho Shimabukuro (first round) Li Tu (final)
Jurij Rodionov (first round)
Constant Lestienne (semifinals)| Semifinals | Final | ||||||||||||
| 8 | Constant Lestienne | 2 | 6 | 63 | |||||||||
| 6 | Li Tu | 6 | 3 | 77 | |||||||||
| 6 | Li Tu | 77 | 4 | 2 | |||||||||
| Yuta Shimizu | 64 | 6 | 6 | ||||||||||
| Yuta Shimizu | 6 | 6 | |||||||||||
 Benjamin Hassan | 2 | 3 | |||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | M Bellucci | 6 | 4 | 3 | |||||||||||||||||||||||
 T-l Wu | 4 | 6 | 6 | T-l Wu | 79 | 2 | 66 | ||||||||||||||||||||
 A Zakharov | 6 | 6 | A Zakharov | 67 | 6 | 78 | |||||||||||||||||||||
| R Noguchi | 4 | 4 | A Zakharov | 4 | 2 | ||||||||||||||||||||||
 M Dodig | 4 | 6 | 4 | 8 | C Lestienne | 6 | 6 | ||||||||||||||||||||
 N Basilashvili | 6 | 2 | 6 | N Basilashvili | 3 | 2r | |||||||||||||||||||||
| Q |  C Negritu | 6 | 5 | 4 | 8 | C Lestienne | 6 | 4 | |||||||||||||||||||
| 8 | C Lestienne | 3 | 7 | 6 | 8 | C Lestienne | 2 | 6 | 63 | ||||||||||||||||||
| 3 | C Wong | 6 | 6 | 6 | L Tu | 6 | 3 | 77 | |||||||||||||||||||
| WC | Lennon Roark Jones | 2 | 1 | 3 | C Wong | 77 | 6 | ||||||||||||||||||||
| Q |  J-s Nam | 2 | 2 | S Mochizuki | 62 | 3 | |||||||||||||||||||||
| S Mochizuki | 6 | 6 | 3 | C Wong | 0 | 4 | |||||||||||||||||||||
 A Blockx | 1r | 6 | L Tu | 6 | 6 | ||||||||||||||||||||||
| Q | P Sekulic | 5 | Q | P Sekulic | 65 | 3 | |||||||||||||||||||||
| Y Demin | 1 | 0r | 6 | L Tu | 77 | 6 | |||||||||||||||||||||
| 6 | L Tu | 6 | 3 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 7 | J Rodionov | 2 | 4 | ||||||||||||||||||||||||
| WC | R Sakamoto | 6 | 6 | WC | R Sakamoto | 7 | 6 | ||||||||||||||||||||
| Q | Federico Cinà | 6 | 3 | 6 | Q | F Cinà | 5 | 4 | |||||||||||||||||||
 G den Ouden | 4 | 6 | 4 | WC | R Sakamoto | 3 | 77 | 63 | |||||||||||||||||||
| WC | M Imamura | 6 | 4 | 6 | Y Shimizu | 6 | 64 | 77 | |||||||||||||||||||
| D Sweeny | 3 | 6 | 3 | WC | M Imamura | 4 | 64 | ||||||||||||||||||||
| Y Shimizu | 78 | 6 | Y Shimizu | 6 | 77 | ||||||||||||||||||||||
| 4 | A Bolt | 66 | 1 | Y Shimizu | 6 | 6 | |||||||||||||||||||||
| 5 | S Shimabukuro | 1 | 4 | B Hassan | 2 | 3 | |||||||||||||||||||||
| B Hassan | 6 | 6 | B Hassan | 6 | 6 | ||||||||||||||||||||||
 D Svrčina | 6 | 6 | D Svrčina | 4 | 1 | ||||||||||||||||||||||
| Q |  J Paul | 3 | 4 | B Hassan | 77 | 68 | 6 | ||||||||||||||||||||
| Q | O Jasika | 3 | 7 | 4 | J McCabe | 61 | 710 | 2 | |||||||||||||||||||
| J McCabe | 6 | 5 | 6 | J McCabe | 5 | 6 | 6 | ||||||||||||||||||||
 E Ymer | 77 | 2 | 77 | E Ymer | 7 | 3 | 3 | ||||||||||||||||||||
| 2 | Y Uchiyama | 61 | 6 | 65 | |||||||||||||||||||||||
Alexander Zverev was the defending champion and successfully defended his title, defeating Alex de Minaur in the final, 6–2, 6–4.
David Goffin was the defending champion, but withdrew before the competition began.
Matthew Ebden was the defending champion but chose not to defend his title.
Peter Polansky was the defending champion but lost in the semifinals to Yasutaka Uchiyama.
Lloyd Harris was the defending champion but chose not to defend his title.
Ričardas Berankis was the defending champion but chose not to defend his title.
Yoshihito Nishioka defeated Denis Shapovalov in the final, 6–4, 7–6(7–5) to win the men's singles tennis title at the 2022 Korea Open. It was his first ATP Tour title since Shenzhen in 2018.
Kwon Soon-woo was the defending champion but chose not to defend his title.
James Duckworth was the defending champion but lost in the quarterfinals to Rinky Hijikata.
Jeremy Beale and Calum Puttergill won the title after defeating Rio Noguchi and Yusuke Takahashi 7–6(7–2), 6–4 in the final.
Kwon Soon-woo was the defending champion but chose not to defend his title.
Yosuke Watanuki was the defending champion and successfully defended his title, defeating Frederico Ferreira Silva 6–7(3–7), 7–5, 6–4 in the final.
Purav Raja and Ramkumar Ramanathan were the defending champions but only Ramanathan chose to defend his title, partnering Arjun Kadhe. Ramanathan lost in the quarterfinals to Marc Polmans and Jason Taylor.
Fernando Verdasco was the defending champion but chose not to defend his title.
Jack Draper was the defending champion but chose not to defend his title.
Li Tu was the defending champion but lost in the first round to Emilio Gómez.
Yasutaka Uchiyama was the defending champion but retired from his second round match against Christopher O'Connell.
Yosuke Watanuki was the defending champion but chose not to defend his title.
Yosuke Watanuki was the defending champion but lost in the second round to Giovanni Fonio.
Steve Johnson was the defending champion but didn't defend his title as he had retired from professional tennis.