| Challenger - Gwangju | 04/18 02:00 | 26 | [171] Lloyd Harris v Yunseong Chung [383] | 6-4,6-4 | |
| Challenger - Gwangju | 04/16 03:15 | 25 | [383] Yunseong Chung v Paul Jubb [385] | 6-4,4-6,6-3 | |
| Challenger - Busan | 04/09 05:30 | 25 | [387] Yun-Seong Chung v Mark Lajal [211] | 3-6,2-6 | |
| Challenger - Busan | 04/08 02:30 | 19 | [331] Hiroki Moriya v Yun-Seong Chung [388] | 4-6,6-7 | |
| Challenger - Busan | 04/07 05:15 | 14 | [430] Stefanos Sakellaridis v Yun-Seong Chung [388] | 6-1,2-6,3-6 | |
| ITF - M15 - Tsukuba | 03/29 06:45 | 27 | Yun-Seong Chung v Hikaru Shiraishi | 6-2,4-6,4-6 | |
| ITF - M15 - Tsukuba | 03/28 01:30 | 26 | Yun-Seong Chung v Takuya Kumasaka | 7-6,1-6,6-4 | |
| ITF - M15 - Tsukuba | 03/27 00:55 | 25 | Yun-Seong Chung v Yu Tanaka | 6-3,7-6 | |
| ITF - M15 - Nishi-Tokyo | 03/23 01:00 | 26 | Takuya Kumasaka v Yunseong Chung | Cancelled | |
| ITF - M15 - Nishi-Tokyo | 03/22 04:05 | 27 | Duckhee Lee v Yunseong Chung | 6-4,6-0 | |
| ITF - M15 - Nishi-Tokyo | 03/21 00:55 | 26 | Linang Xiao v Yunseong Chung | 2-6,4-6 | |
| ITF - M15 - Nishi-Tokyo | 03/20 02:30 | 25 | Masamichi Imamura v Yunseong Chung | 6-7,2-6 | |
| Challenger - Neu-Delhi | 02/25 11:45 | 14 | Siddharth Vishwakarma v Yunseong Chung | Retired | |
| Challenger - Pune | 02/19 05:30 | 19 | Alexey Zakharov v Yunseong Chung | 6-3,5-7,6-4 | |
| Challenger - Pune | 02/18 08:15 | 14 | [379] Yunseong Chung v Rio Noguchi [334] | 7-5,7-6 | |
| Challenger - Bengaluru | 02/12 06:20 | 19 | [307] Chun Hsin Tseng v Yunseong Chung [381] | 7-5,4-6,6-2 | |
| Challenger - Bengaluru | 02/11 09:30 | 14 | Adil Kalyanpur v Yunseong Chung | 4-6,3-6 | |
| Challenger - Nonthaburi | 01/08 05:40 | 19 | Yunseong Chung v Christian Langmo | 2-6,0-6 | |
| Challenger - Nonthaburi | 01/07 07:20 | 14 | Yunseong Chung v Congsup Congcar | 7-5,6-1 | |
| Challenger - Nonthaburi | 12/31 06:25 | 14 | [372] Yunseong Chung v Kaichi Uchida [307] | 4-6,0-6 | |
| Challenger - Yokohama | 11/21 07:20 | 25 | [357] Yunseong Chung v Luca Nardi [118] | 2-6,4-6 | |
| Challenger - Yokohama | 11/20 03:35 | 19 | [301] Yasutaka Uchiyama v Yunseong Chung [362] | 6-4,6-7,7-6 | |
| Challenger - Yokohama | 11/19 05:25 | 14 | [429] Fajing Sun v Yunseong Chung [362] | 4-6,4-6 | |
| Challenger - Kobe | 11/16 02:00 | 26 | [362] Yunseong Chung v Jason Jung [242] | Retired | |
| Challenger - Kobe | 11/14 01:30 | 25 | Renta Tokuda v Yunseong Chung | 6-4,1-6,2-6 | |
| Challenger - Kobe | 11/13 01:30 | 19 | [400] Rio Noguchi v Yunseong Chung [362] | 1-6,4-6 | |
| Challenger - Kobe | 11/12 02:25 | 14 | Sanhui Shin v Yunseong Chung | 3-6,3-6 | |
| ATP - Newport | 07/18 22:05 | 25 | [322] Yunseong Chung v Steve Johnson [197] | 2-6,3-6 | |
| ATP - Newport | 07/17 19:45 | 19 | [242] Beibit Zhukayev v Yunseong Chung [322] | 4-6,3-6 | |
| ATP - Newport | 07/17 15:00 | 14 | Gage Brymer v Yunseong Chung | 3-6,6-7 |
Chung Yun-seong (kor.: 정윤성; * 27. März 1998 in Seoul) ist ein südkoreanischer Tennisspieler.