| 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.
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 | |||||||||||||||||||||||
Els Callens and Meilen Tu were the defending champions but they competed with different partners that year. Callens partnered with Shinobu Asagoe, and lost in the first round to Eleni Daniilidou and Katarina Srebotnik. Tu partnered with Tina Križan, and lost in the quarterfinals to Maria Kirilenko and Maria Sharapova.
Vera Zvonareva was the defending champion, but chose not to participate this year.
Félix Auger-Aliassime and Denis Shapovalov were the defending champions, however Shapovalov withdrew due to injury. Auger-Aliassime played alongside Benjamin Sigouin, but lost in the final to Juan Carlos Aguilar and Felipe Meligeni Alves, 3–6, 6–7(4–7).
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.
Frances Tiafoe was the defending champion, but lost in the first round to Dan Evans.
Peter Polansky was the defending champion but lost in the semifinals to Yasutaka Uchiyama.
Rogério Dutra Silva was the defending champion but chose not to defend his title.
Tatsuma Ito was the defending champion but retired in the second round to Tseng Chun-hsin.
Ričardas Berankis was the defending champion but chose not to defend his title.
Valentin Vacherot was the defending champion but lost in the quarterfinals to Beibit Zhukayev.
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.
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.
Li Tu was the defending champion but lost in the first round to Emilio Gómez.
Christopher O'Connell 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.