| Singles | |
|---|---|
| 2022 Seoul Open Challenger | |
| Champion |  Li Tu |
| Runner-up |  Wu Yibing |
| Score | 7–6(7–5), 6–4 |
Kwon Soon-woo was the defending champion [1] but chose not to defend his title.
Qualifier Li Tu won his first Challenger title, defeating Wu Yibing 7–6(7–5), 6–4 in the final.
Radu Albot (first round)
Tseng Chun-hsin (first round) Alexei Popyrin (first round)
Emilio Gómez (first round) Christopher O'Connell (quarterfinals) James Duckworth (semifinals)
Steve Johnson (second round)
Kamil Majchrzak (semifinals)| Semifinals | Final | ||||||||||||
| Wu Yibing | 6 | 3 | 6 | ||||||||||
| 8 | Kamil Majchrzak | 3 | 6 | 4 | |||||||||
| Wu Yibing | 65 | 4 | |||||||||||
| Q | Li Tu | 77 | 6 | ||||||||||
| Q | Li Tu | 6 | 6 | ||||||||||
| 6 | James Duckworth | 4 | 3 | ||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 1 | R Albot | 0 | 6 | 2 | |||||||||||||||||||||||
| Y Wu | 6 | 4 | 6 | Y Wu | 6 | 6 | |||||||||||||||||||||
 C-M Stebe | 7 | 66 | 6 | C-M Stebe | 2 | 4 | |||||||||||||||||||||
| A Vukic | 5 | 78 | 4 | Y Wu | 6 | 6 | |||||||||||||||||||||
| C Eubanks | 78 | 4 | 4 |  D Svrčina | 2 | 4 | |||||||||||||||||||||
| D Svrčina | 66 | 6 | 6 | D Svrčina | 6 | 3 | 6 | ||||||||||||||||||||
| WC |  Kim Cheong-eui | 3 | 2 | 7 | S Johnson | 2 | 6 | 1 | |||||||||||||||||||
| 7 | S Johnson | 6 | 6 | Y Wu | 6 | 3 | 6 | ||||||||||||||||||||
| 4 | E Gómez | 7 | 4 | 4 | 8 | K Majchrzak | 3 | 6 | 4 | ||||||||||||||||||
| Q |  S Mochizuki | 5 | 6 | 6 | Q | S Mochizuki | 6 | 2 | 6 | ||||||||||||||||||
| PR | M Polmans | 6 | 3 | 4 | Q |  M Neuchrist | 4 | 6 | 4 | ||||||||||||||||||
| Q | M Neuchrist | 3 | 6 | 6 | Q | S Mochizuki | 3 | 0 | |||||||||||||||||||
| J Millman | 6 | 6 | 8 | K Majchrzak | 6 | 6 | |||||||||||||||||||||
| Q | H Moriya | 3 | 1 | J Millman | 6 | 3 | 2 | ||||||||||||||||||||
 J Clarke | 2 | 2 | 8 | K Majchrzak | 2 | 6 | 6 | ||||||||||||||||||||
| 8 | K Majchrzak | 6 | 6 | ||||||||||||||||||||||||
| First round | Second round | Quarterfinals | Semifinals | ||||||||||||||||||||||||
| 5 | C O'Connell | 5 | 6 | 78 | |||||||||||||||||||||||
| R Peniston | 7 | 3 | 66 | 5 | C O'Connell | 6 | 6 | ||||||||||||||||||||
| WC | Kim Jang-jun | 1 | 2 | R Hijikata | 4 | 1 | |||||||||||||||||||||
| R Hijikata | 6 | 6 | 5 | C O'Connell | 4 | 77 | 1 | ||||||||||||||||||||
| K Uchida | 4 | 0 | Q | L Tu | 6 | 64 | 6 | ||||||||||||||||||||
| Q | L Tu | 6 | 6 | Q | L Tu | 6 | 6 | ||||||||||||||||||||
| Q | N Nakagawa | 3 | 7 | 78 | Q | N Nakagawa | 3 | 2 | |||||||||||||||||||
| 3 | A Popyrin | 6 | 5 | 66 | Q | L Tu | 6 | 6 | |||||||||||||||||||
| 6 | J Duckworth | 78 | 6 | 6 | J Duckworth | 4 | 3 | ||||||||||||||||||||
| Q | A Kovacevic | 66 | 3 | 6 | J Duckworth | 78 | 6 | ||||||||||||||||||||
| WC | Ho Chung | 4 | 6 | 3 | WC | Ho Chung | 66 | 1 | |||||||||||||||||||
 Z Piros | 6 | 3 | 0r | 6 | J Duckworth | 4 | 78 | 6 | |||||||||||||||||||
 K Coppejans | 6 | 6 | M Marterer | 6 | 66 | 3 | |||||||||||||||||||||
| T-l Wu | 3 | 4 | K Coppejans | 3 | 4 | ||||||||||||||||||||||
| M Marterer | 6 | 6 | M Marterer | 6 | 6 | ||||||||||||||||||||||
| 2 | C-h Tseng | 3 | 2 | ||||||||||||||||||||||||
Sergiy Stakhovsky was the defending champion but chose not to defend his title.
Jason Jung was the defending champion but chose not to defend his title.
Ričardas Berankis was the defending champion but chose not to defend his title.
James Duckworth was the defending champion but chose not to defend his title.
Yūichi Sugita was the defending champion but chose not to defend his title.
Yūichi Sugita was the defending champion but chose not to defend his title.
Janko Tipsarević was the defending champion but chose not to defend his title.
Evgeny Donskoy was the defending champion but chose not to defend his title.
Yasutaka Uchiyama was the defending champion but chose not to defend his title.
Mackenzie McDonald was the defending champion but chose not to defend his title.
Fabio Fognini was the defending champion, but lost in the quarterfinals to Taylor Fritz.
Alexei Popyrin was the defending champion but chose not to defend his title.
This was the first edition of the tournament.
Novak Djokovic defeated John Millman in the final, 6–3, 6–2 to win the 2019 Japan Open.
Roger Federer was the two-time defending champion and successfully defended his title, defeating Alex de Minaur in the final, 6–2, 6–2. He did not lose a single set in the entire tournament. The victory made Federer the first player in ATP history to win 10 same tournament titles on two different surfaces. It was his 103rd and final ATP title before announcing his retirement in 2022.
This was the second of seven editions of the tournament in the 2021 tennis season. Illya Marchenko was the defending champion but lost in the quarterfinals to Andreas Seppi.
John Millman was the defending champion, but lost in the quarterfinals to James Duckworth.
Dan Evans was the defending champion but chose not to defend his title.
Ričardas Berankis was the defending champion but chose not to defend his title.
Kwon Soon-woo defeated Roberto Bautista Agut in the final, 6–4, 3–6, 7–6(7–4) to win the men's singles tennis title at the 2023 Adelaide International 2. It was his second ATP Tour singles title, and he became just the tenth man in ATP Tour history to win a title as a lucky loser.