| ITF M25 Tsukuba | 03/29 00:30 | 25 | Kazuki Nishiwaki v Yunseong Chung | 6-2,6-3 | |
| Challenger de Pune | 02/28 13:00 | 25 | [241] Miljan Zekic v Yunseong Chung [358] | 6-3,6-4 | |
| Challenger de Pune | 02/27 07:05 | 19 | [299] Jay Clarke v Yunseong Chung [359] | 6-7,3-6 | |
| Challenger de Pune | 02/26 10:30 | 14 | Nitin Kumar Sinha v Yunseong Chung | 2-6,2-6 | |
| Challenger Bengaluru | 02/20 07:25 | 19 | [320] Nikola Milojevic v Yunseong Chung [359] | 7-6,6-4 | |
| Challenger Bengaluru | 02/19 11:15 | 14 | [424] Dayne Kelly v Yunseong Chung [360] | 6-7,4-6 | |
| Challenger de Manama | 02/12 08:00 | 14 | Yunseong Chung v Aleksandr Braynin | 5-7,4-6 | |
| Challenger de Concepción | 01/22 15:30 | 14 | [128] Karol Drzewiecki v Yunseong Chung [335] | 6-3,6-2 | |
| Challenger de Piracicaba | 01/17 17:15 | 25 | [385] Carlos Sanchez Jover v Yunseong Chung [335] | 6-3,6-0 | |
| Challenger de Piracicaba | 01/16 15:10 | 19 | [335] Yunseong Chung v Carlos Sanchez Jover [385] | 6-4,6-3 | |
| Challenger de Piracicaba | 01/15 18:15 | 14 | Yunseong Chung v Gonzalo Bueno | 6-2,6-2 | |
| Challenger de Piracicaba | 01/15 17:00 | 14 | Yunseong Chung v Mateus D C C Alves | Cancelled | |
| Challenger de Tigre | 01/10 17:10 | 25 | [332] Yunseong Chung v Edoardo Lavagno [366] | 3-6,1-6 | |
| Challenger de Yokkaichi | 11/25 04:10 | 27 | [361] Yunseong Chung v Yosuke Watanuki [173] | Retired | |
| Challenger de Yokkaichi | 11/24 01:30 | 26 | [361] Yunseong Chung v Mukund Sasikumar [353] | 6-1,6-4 | |
| Challenger de Yokkaichi | 11/21 02:50 | 25 | [248] Dane Sweeny v Yunseong Chung [363] | 5-7,2-6 | |
| Challenger de Kobe | 11/15 02:50 | 25 | [363] Yunseong Chung v Yosuke Watanuki [196] | 2-6,2-6 | |
| Challenger de Kobe | 11/14 02:45 | 19 | [362] Yunseong Chung v Yuta Shimizu [404] | 6-2,7-6 | |
| Challenger de Kobe | 11/13 05:30 | 14 | Yunseong Chung v Duckhee Lee | 6-2,6-0 | |
| Challenger de Yokohama | 11/02 03:25 | 26 | [384] Yunseong Chung v Kaichi Uchida [172] | 6-7,3-6 | |
| Challenger de Yokohama | 11/01 02:55 | 25 | Masamichi Imamura v Yunseong Chung | 3-6,4-6 | |
| Challenger de Busan | 10/20 02:00 | 26 | [470] Seong Chan Hong v Yunseong Chung [395] | 6-3,7-5 | |
| Challenger de Busan | 10/18 06:35 | 25 | [395] Yunseong Chung v Chun Hsin Tseng [86] | 7-5,7-5 | |
| Challenger Gwangju | 10/04 05:30 | 25 | [397] Yunseong Chung v Jisung Nam [222] | 6-1,3-6,5-7 | |
| Challenger Gwangju | 10/03 04:00 | 19 | [397] Yunseong Chung v Seita Watanabe [401] | 6-2,7-6 | |
| ATP Seúl | 09/27 10:00 | 25 | [121] Soonwoo Kwon v Yunseong Chung [426] | 7-6,6-7,6-1 | |
| ATP Seúl | 09/25 03:50 | 19 | [412] Shintaro Mochizuki v Yunseong Chung [415] | 5-7,4-6 | |
| ATP Seúl | 09/24 06:55 | 14 | [415] Yunseong Chung v Dalibor Svrcina [212] | 6-3,4-6,6-1 | |
| Challenger de Nonthaburi | 09/05 11:00 | 25 | [242] Yosuke Watanuki v Yunseong Chung [418] | Retired | |
| Challenger de Nonthaburi | 08/30 08:15 | 25 | [418] Yunseong Chung v Billy Harris [305] | 3-6,6-4,4-6 |
Chung Yun-seong (Korean: 정윤성; born 27 March 1998) is a South Korean tennis player.
Chung has a career high ATP singles ranking of No. 233 achieved on 22 July 2019. He also has a career high ATP doubles ranking of No. 129 achieved on 22 May 2023. Chung has won three doubles ATP Challenger titles as well as four ITF singles and five doubles titles.
On the junior tour, Chung had a career-high combined ranking of 3 achieved on 21 March 2016. Chung was a semifinalist at the 2016 Australian Open boys' singles event and the 2015 US Open boys' singles event where he fell to both eventual champions Oliver Anderson and Taylor Fritz, respectively. Chung was also a singles finalist at the Osaka Mayor's Cup in 2014.
He and Orlando Luz lost to Yishai Oliel of Israel and Patrik Rikl of the Czech Republic in the final of the 2016 French Open boys' doubles, 6–3, 6–4.