| Challenger - Lexington | 08/01 01:15 | 25 | Yunseong Chung v William Bushamuka | 6-2,6-3 | |
| Challenger Binghamton | 07/25 14:30 | 25 | [225] Jay Clarke v Yunseong Chung [335] | 6-1,7-6 | |
| Challenger Gatineau | 07/18 17:20 | 26 | [143] Bradley Klahn v Yunseong Chung [354] | 7-5,6-4 | |
| Challenger Gatineau | 07/17 20:55 | 25 | [354] Yunseong Chung v Mitchell Krueger [216] | 7-6,6-4 | |
| Challenger Gatineau Qual | 07/16 16:30 | 54 | Justin Boulais v Yunseong Chung | 2-6,1-6 | |
| Challenger Gatineau Qual | 07/15 18:50 | 46 | [416] Alejandro Gomez v Yunseong Chung [369] | 3-6,6-7 | |
| Challenger Gatineau Qual | 07/14 17:50 | 45 | Tyler Lu v Yunseong Chung | 6-3,3-6,4-6 | |
| Challenger - Winnipeg | 07/12 20:00 | 26 | [369] Yunseong Chung v Go Soeda [178] | 2-6,6-2,4-6 | |
| Challenger - Winnipeg | 07/10 18:20 | 25 | David Volfson v Yunseong Chung | 3-6,3-6 | |
| Challenger Winnipeg Qual | 07/09 16:40 | 54 | Yunseong Chung v Jack Mingjie Lin | 6-2,6-2 | |
| Challenger Winnipeg Qual | 07/08 21:50 | 46 | Yunseong Chung v Yshai Oliel | 6-3,6-1 | |
| ITF Korea F3 | 06/24 05:00 | 29 | Yunseong Chung v Ji Sung Nam | 6-1,6-3 | |
| ITF Korea F3 | 06/23 02:00 | 28 | [247] Soonwoo Kwon v Yunseong Chung [454] | 4-6,4-6 | |
| ITF Korea F3 | 06/22 03:00 | 27 | Yunseong Chung v Oh-Hee Kwon | 6-4,6-1 | |
| ITF Korea F3 | 06/20 02:30 | 26 | Yunseong Chung v Min-Kyu Song | 7-6,7-6 | |
| ITF Korea F3 | 06/19 06:00 | 25 | Yunseong Chung v Ju-Hae Moon | 6-3,4-6,7-5 | |
| ITF Korea F2 | 06/17 04:00 | 29 | Ji Sung Nam v Yunseong Chung | 4-6,3-6 | |
| ITF Korea F2 | 06/16 02:40 | 28 | Jae Hwan Kim v Yunseong Chung | 4-6,7-5,2-6 | |
| ITF Korea F2 | 06/15 03:20 | 27 | Chan-Yeong Oh v Yunseong Chung | 6-7,6-3,4-6 | |
| ITF Korea F2 | 06/14 03:45 | 26 | Soichiro Moritani v Yunseong Chung | 6-7,0-6 | |
| ITF Korea F2 | 06/12 01:00 | 25 | Clement Larriere v Yunseong Chung | 3-6,4-6 | |
| ITF China F7 | 06/01 06:15 | 27 | [221] Xin Gao v Yunseong Chung [450] | 6-0,6-7,6-3 | |
| ITF China F7 | 05/31 04:30 | 26 | Chien Hsun Lo v Yunseong Chung | 2-6,7-5,5-7 | |
| ITF China F7 | 05/29 05:30 | 25 | Zhenxiong Dong v Yunseong Chung | 2-6,1-6 | |
| Challenger - Busan | 05/15 03:25 | 25 | [85] Matthew Ebden v Yunseong Chung [464] | 6-3,3-6,6-3 | |
| Challenger Busan Qual | 05/14 02:00 | 54 | [442] Yunseong Chung v Luke Saville [456] | 6-7,7-6,6-0 | |
| Challenger Busan Qual | 05/13 04:00 | 46 | [161] Jason Kubler v Yunseong Chung [442] | 3-6,2-6 | |
| Challenger Busan Qual | 05/12 02:55 | 45 | Yunseong Chung v Ben Patael | 6-3,6-2 | |
| Challenger Gimcheon | 05/08 04:05 | 25 | [89] Jordan Thompson v Yunseong Chung [442] | 6-4,6-1 | |
| Challenger - Soul | 05/01 06:00 | 25 | [232] Lloyd Harris v Yunseong Chung [440] | 5-7,6-3,6-0 |
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.