# 2023 Seoul Open Challenger – Singles

Li Tu was the defending champion but lost in the first round to Emilio Gómez.
Bu Yunchaokete won the title after defeating Aleksandar Vukic 7–6$^{(7–4)}$, 6–4 in the final.

## Seeds

* Max Purcell (second round)
* Christopher Eubanks (quarterfinals)
* Jordan Thompson (second round)
* James Duckworth (second round)
* Emilio Gómez (second round)
* Rinky Hijikata (quarterfinals)
* Aleksandar Vukic (final)
* Denis Kudla (quarterfinals)

## Draw
### Key

* Q = Qualifier
* WC = Wild card
* LL = Lucky loser
* Alt = Alternate
* SE = Special exempt
* PR = Protected ranking
* ITF = ITF entry
* JE = Junior exempt
* w/o = Walkover
* r = Retired
* d = Defaulted
* SR = Special ranking

### Finals

| Semifinals | Semifinals | Semifinals | Semifinals | Final | Final | Final | Final |
| | Bu Yunchaokete | 7$^7$ | 6 | | | | |
| Q | Yasutaka Uchiyama | 6$^4$ | 4 | | | | |
| Q | Yasutaka Uchiyama | 6$^4$ | 4 | | Bu Yunchaokete | 7$^7$ | 6 |
| | | | | 7 | Aleksandar Vukic | 6$^4$ | 4 |
| WC | Chung Yun-seong | 6$^5$ | 1 | 7 | Aleksandar Vukic | 6$^4$ | 4 |
| 7 | Aleksandar Vukic | 7$^7$ | 6 | | | | |

### Top half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 1 | M Purcell | 6 | 6 | | | | | | | | | | | | | | | |
| Q | J-s Nam | 3 | 4 | | 1 | M Purcell | 1 | 3 | | | | | | | | | | |
| | S-c Hong | 6 | 6 | | | S-c Hong | 6 | 6 | | | | | | | | | | |
| Q | T Ito | 3 | 2 | | | | | | | | S-c Hong | 4 | 4 | | | | | |
| | A Çelikbilek | 6 | 3 | 1 | | | | | | | Y Bu | 6 | 6 | | | | | |
| | Y Bu | 3 | 6 | 6 | | Y Bu | 6 | 6$^1$ | 6 | | | | | | | | | |
| | L Tu | 6$^4$ | 5 | | 5 | E Gómez | 4 | 7$^7$ | 3 | | | | | | | | | |
| 5 | E Gómez | 7$^7$ | 7 | | | | | | | | | | | | | Y Bu | 7$^7$ | 6 |
| 4 | J Duckworth | 7$^7$ | 1 | 6 | | | | | | | | | | | Q | Y Uchiyama | 6$^4$ | 4 |
| Q | D-h Lee | 6$^4$ | 6 | 1 | 4 | J Duckworth | 4 | 2 | | | | | | | | | | |
| Q | M Sasikumar | 4 | 7$^{13}$ | 0 | Q | Y Uchiyama | 6 | 6 | | | | | | | | | | |
| Q | Y Uchiyama | 6 | 6$^{11}$ | 6 | | | | | | Q | Y Uchiyama | 6 | 4 | 6 | | | | |
| | M Polmans | 6 | 6 | | | | | | | 8 | D Kudla | 3 | 6 | 1 | | | | |
| WC | J-m Lee | 3 | 2 | | | M Polmans | 7 | 4 | 3 | | | | | | | | | |
| PR | T-S Kwiatkowski | 1 | 0 | | 8 | D Kudla | 5 | 6 | 6 | | | | | | | | | |
| 8 | D Kudla | 6 | 6 | | | | | | | | | | | | | | | |

### Bottom half

| First round | First round | First round | First round | First round | Second round | Second round | Second round | Second round | Second round | Quarterfinals | Quarterfinals | Quarterfinals | Quarterfinals | Semifinals | Semifinals | Semifinals | Semifinals |
| 6 | R Hijikata | 6 | 7$^7$ | | | | | | | | | | | | | | |
| | S Shimabukuro | 4 | 6$^3$ | | 6 | R Hijikata | 6 | 6 | | | | | | | | | |
| Alt | E Donskoy | 4 | 6 | 6 | Alt | E Donskoy | 3 | 4 | | | | | | | | | |
| | B Holt | 6 | 4 | 2 | | | | | | 6 | R Hijikata | 2 | 3 | | | | |
| WC | Y-s Chung | 6 | 6 | | | | | | | WC | Y-s Chung | 6 | 6 | | | | |
| Q | P Gojowczyk | 2 | 3 | | WC | Y-s Chung | 6 | 6 | | | | | | | | | |
| WC | Hy Chung | 2 | 4 | | 3 | J Thompson | 4 | 3 | | | | | | | | | |
| 3 | J Thompson | 6 | 6 | | | | | | | | | | | WC | Y-s Chung | 6$^5$ | 1 |
| 7 | A Vukic | 7$^7$ | 7$^7$ | | | | | | | | | | | 7 | A Vukic | 7$^7$ | 6 |
| | L Harris | 6$^3$ | 6$^0$ | | 7 | A Vukic | 6 | 6$^5$ | 6 | | | | | | | | |
| | C İlkel | 7$^7$ | 2 | 4 | | R Berankis | 3 | 7$^7$ | 1 | | | | | | | | |
| | R Berankis | 6$^2$ | 6 | 6 | | | | | | 7 | A Vukic | 7 | 6 | | | | |
| | G Diallo | 6 | 6 | | | | | | | 2 | C Eubanks | 5 | 3 | | | | |
| | Y-h Hsu | 2 | 3 | | | G Diallo | 6 | 3 | 2 | | | | | | | | |
| | Y Shimizu | 3 | 6 | 5 | 2 | C Eubanks | 2 | 6 | 6 | | | | | | | | |
| 2 | C Eubanks | 6 | 3 | 7 | | | | | | | | | | | | | |