| Challenger - Gwangju | 05/15 03:40 | 25 | [241] Duckhee Lee v Yunseong Chung [253] | 4-6,2-6 | |
| Challenger - Gwangju | 05/14 05:00 | 24 | Jea Moon Lee v Yunseong Chung | 6-7,2-6 | |
| Challenger - Busan | 05/10 07:05 | 27 | [95] Ricardas Berankis v Yunseong Chung [270] | 5-7,6-3,6-4 | |
| Challenger - Busan | 05/09 06:45 | 26 | [270] Yunseong Chung v Marcos Baghdatis [133] | 6-2,6-3 | |
| Challenger - Busan | 05/07 04:05 | 25 | [139] Nikola Milojevic v Yunseong Chung [270] | 2-6,6-3,5-7 | |
| Challenger - Busan | 05/06 04:10 | 24 | [271] Yunseong Chung v Zhe Li [248] | 3-6,6-3,6-4 | |
| Challenger - Seoul | 05/02 04:00 | 26 | [227] Yasutaka Uchiyama v Yunseong Chung [271] | 6-4,6-4 | |
| Challenger - Seoul | 05/01 05:20 | 25 | [271] Yunseong Chung v Yuichi Sugita [182] | 6-2,6-3 | |
| Challenger - Seoul | 04/29 07:55 | 24 | [277] Stephane Robert v Yunseong Chung [271] | 6-1,2-6,4-6 | |
| Challenger Nanchang | 04/23 05:55 | 25 | [208] Adam Pavlasek v Yunseong Chung [267] | 6-3,6-2 | |
| Challenger Nanchang | 04/22 04:45 | 24 | Rio Noguchi v Yunseong Chung | 4-6,3-6 | |
| Challenger Anning | 04/16 04:30 | 25 | [213] Adam Pavlasek v Yunseong Chung [261] | Retired | |
| Challenger Anning | 04/15 03:15 | 24 | Yunseong Chung v Hanyi Liu | 6-1,6-3 | |
| Challenger - Taipei | 04/08 08:20 | 24 | [263] Yunseong Chung v Maverick Banes [272] | 6-2,6-7,4-6 | |
| Challenger - Zhangjiagang | 03/21 02:00 | 26 | [223] Viktor Galovic v Yunseong Chung [266] | 6-3,6-2 | |
| Challenger - Zhangjiagang | 03/20 02:00 | 25 | [266] Yunseong Chung v Yuichi Sugita [178] | 4-6,7-5,6-2 | |
| Challenger - Zhangjiagang | 03/19 03:15 | 24 | [266] Yunseong Chung v Fajing Sun [329] | 6-4,6-4 | |
| Challenger - Shenzhen | 03/14 02:30 | 26 | [280] Yunseong Chung v Stefano Napolitano [229] | 7-5,2-6,6-7 | |
| Challenger - Shenzhen | 03/12 08:55 | 25 | [180] Rudolf Molleker v Yunseong Chung [280] | 4-6,1-6 | |
| Challenger - Shenzhen | 03/11 05:10 | 24 | [280] Yunseong Chung v Mohamed Safwat [216] | 6-3,6-1 | |
| Challenger - Zhuhai | 03/07 08:50 | 26 | [280] Yunseong Chung v Marcos Baghdatis [129] | 4-6,2-6 | |
| Challenger - Zhuhai | 03/06 07:20 | 25 | [213] Viktor Galovic v Yunseong Chung [280] | 3-6,4-6 | |
| Challenger - Zhuhai | 03/05 03:45 | 24 | [280] Yunseong Chung v Harri Heliovaara [374] | 7-5,6-2 | |
| Challenger - 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 - Launceston | 01/30 02:40 | 25 | [278] Yunseong Chung v Lorenzo Giustino [227] | 3-6,7-6,3-6 | |
| Challenger - Launceston | 01/28 05:55 | 24 | Yunseong Chung v Rubin Statham | 6-4,6-3 | |
| Challenger - Burnie | 01/21 23:00 | 25 | [277] Yunseong Chung v Lorenzo Giustino [222] | 2-6,3-6 | |
| Challenger - Burnie | 01/21 00:30 | 24 | [415] Jordi Samper-Montana v Yunseong Chung [277] | 5-7,1-6 |
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.