| Challenger Gwangju | 05/14 05:00 | 24 | Jea Moon Lee v Yunseong Chung | 6-7,2-6 | |
| Challenger de Busan | 05/10 07:05 | 27 | [95] Ricardas Berankis v Yunseong Chung [270] | 5-7,6-3,6-4 | |
| Challenger de Busan | 05/09 06:45 | 26 | [270] Yunseong Chung v Marcos Baghdatis [133] | 6-2,6-3 | |
| Challenger de Busan | 05/07 04:05 | 25 | [139] Nikola Milojevic v Yunseong Chung [270] | 2-6,6-3,5-7 | |
| Challenger de Busan | 05/06 04:10 | 24 | [271] Yunseong Chung v Zhe Li [248] | 3-6,6-3,6-4 | |
| Challenger de Seúl | 05/02 04:00 | 26 | [227] Yasutaka Uchiyama v Yunseong Chung [271] | 6-4,6-4 | |
| Challenger de Seúl | 05/01 05:20 | 25 | [271] Yunseong Chung v Yuichi Sugita [182] | 6-2,6-3 | |
| Challenger de Seúl | 04/29 07:55 | 24 | [277] Stephane Robert v Yunseong Chung [271] | 6-1,2-6,4-6 | |
| Challenger de Nanchang | 04/23 05:55 | 25 | [208] Adam Pavlasek v Yunseong Chung [267] | 6-3,6-2 | |
| Challenger de Nanchang | 04/22 04:45 | 24 | Rio Noguchi v Yunseong Chung | 4-6,3-6 | |
| Challenger de Anning | 04/16 04:30 | 25 | [213] Adam Pavlasek v Yunseong Chung [261] | Retired | |
| Challenger de Anning | 04/15 03:15 | 24 | Yunseong Chung v Hanyi Liu | 6-1,6-3 | |
| Challenger de Taipéi | 04/08 08:20 | 24 | [263] Yunseong Chung v Maverick Banes [272] | 6-2,6-7,4-6 | |
| Challenger de Zhangjiagang | 03/21 02:00 | 26 | [223] Viktor Galovic v Yunseong Chung [266] | 6-3,6-2 | |
| Challenger de Zhangjiagang | 03/20 02:00 | 25 | [266] Yunseong Chung v Yuichi Sugita [178] | 4-6,7-5,6-2 | |
| Challenger de Zhangjiagang | 03/19 03:15 | 24 | [266] Yunseong Chung v Fajing Sun [329] | 6-4,6-4 | |
| Challenger de Shenzhen | 03/14 02:30 | 26 | [280] Yunseong Chung v Stefano Napolitano [229] | 7-5,2-6,6-7 | |
| Challenger de Shenzhen | 03/12 08:55 | 25 | [180] Rudolf Molleker v Yunseong Chung [280] | 4-6,1-6 | |
| Challenger de Shenzhen | 03/11 05:10 | 24 | [280] Yunseong Chung v Mohamed Safwat [216] | 6-3,6-1 | |
| Challenger de Zhuhai | 03/07 08:50 | 26 | [280] Yunseong Chung v Marcos Baghdatis [129] | 4-6,2-6 | |
| Challenger de Zhuhai | 03/06 07:20 | 25 | [213] Viktor Galovic v Yunseong Chung [280] | 3-6,4-6 | |
| Challenger de Zhuhai | 03/05 03:45 | 24 | [280] Yunseong Chung v Harri Heliovaara [374] | 7-5,6-2 | |
| Challenger de Yokohama | 02/25 02:40 | 24 | [280] Yunseong Chung v Tsung-Hua Yang [287] | 4-6,3-6 | |
| Challenger Bangkok 1A | 02/19 03:00 | 25 | [213] Gianluca Mager v Yunseong Chung [280] | 6-4,6-4 | |
| Challenger Bangkok 1A | 02/18 05:20 | 24 | [280] Yunseong Chung v Pedro Cachin [235] | 6-2,6-1 | |
| Challenger de Launceston | 01/30 02:40 | 25 | [278] Yunseong Chung v Lorenzo Giustino [227] | 3-6,7-6,3-6 | |
| Challenger de Launceston | 01/28 05:55 | 24 | Yunseong Chung v Rubin Statham | 6-4,6-3 | |
| Challenger de Burnie | 01/21 23:00 | 25 | [277] Yunseong Chung v Lorenzo Giustino [222] | 2-6,3-6 | |
| Challenger de Burnie | 01/21 00:30 | 24 | [415] Jordi Samper-Montana v Yunseong Chung [277] | 5-7,1-6 | |
| Challenger de Canberra | 01/07 00:40 | 25 | [274] Yunseong Chung v Brydan Klein [407] | 6-7,7-6,0-6 |
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.