| Challenger Lugano | 03/29 12:15 | 25 | [367] Yunseong Chung v Yuichi Sugita [229] | 3-6,4-6 | |
| Challenger Lugano | 03/28 10:10 | 19 | [306] Lucas Miedler v Yunseong Chung [367] | 3-6,4-6 | |
| Challenger Lugano | 03/27 13:40 | 14 | [456] Antoine Bellier v Yunseong Chung [367] | 6-7,2-6 | |
| Challenger de Biena | 03/20 15:30 | 14 | [365] Yunseong Chung v Marek Gengel [430] | 6-3,4-6,3-6 | |
| Challenger de Cleveland | 01/30 20:35 | 14 | [416] Yunseong Chung v Michael Geerts [339] | Retired | |
| ITF M25 Monastir | 01/23 09:45 | 29 | [416] Yunseong Chung v Harold Mayot [471] | 4-6,6-0,4-6 | |
| ITF M25 Monastir | 01/22 09:00 | 28 | Yunseong Chung v Titouan Droguet | 7-6,6-4 | |
| ITF M25 Monastir | 01/21 12:30 | 27 | Gleb Sakharov v Yunseong Chung | 3-6,3-6 | |
| ITF M25 Monastir | 01/20 11:15 | 26 | Jumpei Yamasaki v Yunseong Chung | 4-6,2-6 | |
| ITF M25 Monastir | 01/18 10:45 | 25 | Alexander Donski v Yunseong Chung | 4-6,2-6 | |
| ITF M25 Monastir | 01/15 08:25 | 27 | [415] Yunseong Chung v Skander Mansouri [438] | 6-4,3-6,4-6 | |
| ITF M25 Monastir | 01/14 12:00 | 26 | Yunseong Chung v Josh Reid | 6-2,6-0 | |
| ITF M25 Monastir | 01/12 08:00 | 25 | Yunseong Chung v Skander Mezouar | 6-0,6-2 | |
| ITF M25 Meitar | 11/06 08:00 | 25 | Ben Patael v Yunseong Chung | Cancelled | |
| ITF M25 Meitar | 11/03 09:55 | 26 | Arnaud Bovy v Yunseong Chung | 6-4,3-6,6-4 | |
| ITF M25 Meitar | 11/02 08:00 | 25 | Joshua Luck v Yunseong Chung | 3-6,1-6 | |
| Challenger de Columbus | 09/21 14:00 | 25 | [419] Yunseong Chung v Ji Sung Nam [382] | 6-3,4-6,6-7 | |
| Challenger de Columbus | 09/20 14:00 | 19 | [367] Alexis Galarneau v Yunseong Chung [419] | 4-6,4-6 | |
| Challenger de Columbus | 09/19 18:35 | 14 | Justin Boulais v Yunseong Chung | 6-7,3-6 | |
| ATP Winston-Salem | 08/21 20:10 | 14 | [415] Yunseong Chung v Yosuke Watanuki [255] | 3-6,6-7 | |
| ITF M25 Decatur | 08/06 17:10 | 27 | Yunseong Chung v Eliot Spizzirri | 4-6,4-6 | |
| ITF M25 Decatur | 08/05 17:55 | 26 | Jumpei Yamasaki v Yunseong Chung | 2-6,2-6 | |
| ITF M25 Decatur | 08/04 18:45 | 25 | Yunseong Chung v Nathan Ponwith | 6-2,6-1 | |
| ITF M25 Champaign | 07/28 17:25 | 25 | Yunseong Chung v Ben Shelton | 5-7,0-6 | |
| Challenger de Nur-Sultan | 07/19 10:05 | 25 | [405] Yunseong Chung v Hugo Grenier [252] | 7-6,3-6,1-6 | |
| Challenger de Nur-Sultan | 07/15 06:00 | 26 | [159] Roman Safiullin v Yunseong Chung [393] | 6-3,6-4 | |
| Challenger de Nur-Sultan | 07/13 07:15 | 25 | [393] Yunseong Chung v Yan Bondarevskiy [464] | 6-3,6-4 | |
| ITF M15 Monastir | 05/28 08:30 | 27 | [443] Thomas Fancutt v Yunseong Chung [409] | Retired | |
| ITF M15 Monastir | 05/27 08:30 | 26 | Yuta Kikuchi v Yunseong Chung | 2-6,6-3,1-6 | |
| ITF M15 Monastir | 05/26 09:30 | 25 | Louis Tessa v Yunseong Chung | 1-6,0-6 |
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.