| Challenger - Salinas | 04/05 20:45 | 25 | Blu Baker v Yunseong Chung | 2-6,3-6 | |
| 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 - Bienna | 03/20 15:30 | 14 | [365] Yunseong Chung v Marek Gengel [430] | 6-3,4-6,3-6 | |
| Challenger - 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 Columbus | 09/21 14:00 | 25 | [419] Yunseong Chung v Ji Sung Nam [382] | 6-3,4-6,6-7 | |
| Challenger Columbus | 09/20 14:00 | 19 | [367] Alexis Galarneau v Yunseong Chung [419] | 4-6,4-6 | |
| Challenger 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 - Nur-Sultã | 07/19 10:05 | 25 | [405] Yunseong Chung v Hugo Grenier [252] | 7-6,3-6,1-6 | |
| Challenger - Nur-Sultã | 07/15 06:00 | 26 | [159] Roman Safiullin v Yunseong Chung [393] | 6-3,6-4 | |
| Challenger - Nur-Sultã | 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 |
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.