| Челленджер Кванджу | 04/18 02:00 | 26 | [171] Ллойд Харрис v Юнсеонг Чон [383] | 6-4,6-4 | |
| Челленджер Кванджу | 04/16 03:15 | 25 | [383] Юнсеонг Чон v Пауль Джубб [385] | 6-4,4-6,6-3 | |
| Челленджер Бусан | 04/09 05:30 | 25 | [387] Юн-Сеонг Чунг v Марк Лаял [211] | 3-6,2-6 | |
| Челленджер Бусан | 04/08 02:30 | 19 | [331] Хироки Мория v Юн-Сеонг Чунг [388] | 4-6,6-7 | |
| Челленджер Бусан | 04/07 05:15 | 14 | [430] Стефанос Сакелларидис v Юн-Сеонг Чунг [388] | 6-1,2-6,3-6 | |
| ITF M15 Цукуба | 03/29 06:45 | 27 | Юн-Сеонг Чунг v Хикару Сираиси | 6-2,4-6,4-6 | |
| ITF M15 Цукуба | 03/28 01:30 | 26 | Юн-Сеонг Чунг v Такуя Кумасака | 7-6,1-6,6-4 | |
| ITF M15 Цукуба | 03/27 00:55 | 25 | Юн-Сеонг Чунг v Yu Tanaka | 6-3,7-6 | |
| ITF M15 Ниситокё | 03/23 01:00 | 26 | Такуя Кумасака v Юнсеонг Чон | CANC | |
| ITF M15 Ниситокё | 03/22 04:05 | 27 | Дакхее Ли v Юнсеонг Чон | 6-4,6-0 | |
| ITF M15 Ниситокё | 03/21 00:55 | 26 | Линанг Сяо v Юнсеонг Чон | 2-6,4-6 | |
| ITF M15 Ниситокё | 03/20 02:30 | 25 | Масамичи Имамура v Юнсеонг Чон | 6-7,2-6 |
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.