| Challenger - Canberra | 01/07 00:40 | 25 | [274] Yunseong Chung v Brydan Klein [407] | 6-7,7-6,0-6 | |
| Challenger - Numeá | 01/01 04:25 | 25 | [274] Yunseong Chung v Jurij Rodionov [217] | 4-6,1-6 | |
| Challenger - Numeá | 12/31 00:30 | 24 | [262] Yunseong Chung v Tomislav Brkic [309] | 6-3,6-2 | |
| ITF - Qatar F5 | 12/11 12:00 | 25 | Yunseong Chung v Kristian Lozan | Cancelled | |
| Open da Austrália - Wild Card | 11/30 05:45 | 27 | Zhe Li v Yunseong Chung | 6-4,6-4 | |
| Open da Austrália - Wild Card | 11/29 03:50 | 26 | [402] Rigele Te v Yunseong Chung [266] | 6-7,1-6 | |
| Challenger - Kobe | 11/16 04:45 | 27 | [281] Yunseong Chung v Tatsuma Ito [163] | 2-6,3-6 | |
| Challenger - Kobe | 11/14 05:00 | 26 | [385] Nam Hoang Ly v Yunseong Chung [281] | 4-6,2-6 | |
| Challenger - Kobe | 11/13 02:00 | 25 | [281] Yunseong Chung v Jelle Sels [266] | 7-6,7-6 | |
| Challenger - Liuzhou | 10/23 03:35 | 25 | [149] Miomir Kecmanovic v Yunseong Chung [282] | Retired | |
| Challenger - Liuzhou | 10/22 04:45 | 54 | [282] Yunseong Chung v Emil Ruusuvuori [318] | 6-3,6-3 | |
| Challenger - Liuzhou | 10/21 07:00 | 46 | Yunseong Chung v Youssef Hossam | 7-5,6-3 | |
| Challenger - Liuzhou | 10/20 08:20 | 45 | Yunseong Chung v Sidharth Rawat | 5-7,6-2,6-3 | |
| Challenger - Ningbo | 10/19 03:00 | 27 | [291] Yunseong Chung v Prajnesh Gunneswaran [170] | 2-6,1-6 | |
| Challenger - Ningbo | 10/17 05:15 | 26 | [291] Yunseong Chung v Yosuke Watanuki [220] | 2-6,7-6,6-3 | |
| Challenger - Ningbo | 10/15 04:05 | 25 | [127] Ramkumar Ramanathan v Yunseong Chung [294] | 6-1,6-7,6-7 | |
| Challenger - Tashkent | 10/07 05:00 | 46 | Yunseong Chung v Artem Dubrivnyy | 3-6,5-7 | |
| Challenger - Tashkent | 10/06 05:00 | 45 | Yunseong Chung v Grigoriy Korobeynikov | 6-0,6-0 | |
| Challenger - Kaohsiung | 09/18 10:00 | 25 | [123] Jason Jung v Yunseong Chung [296] | 6-3,6-4 | |
| Challenger - Kaohsiung | 09/17 04:15 | 54 | [293] Yunseong Chung v Tristan Lamasine [345] | 6-4,6-2 | |
| Challenger - Kaohsiung | 09/16 07:45 | 46 | [293] Yunseong Chung v Xin Gao [276] | 7-5,6-3 | |
| Challenger - Kaohsiung | 09/15 12:10 | 45 | [293] Yunseong Chung v N. Vijay Sundar Prashanth [231] | 7-5,6-2 | |
| Challenger - Xangai | 09/11 07:00 | 25 | [325] Aldin Setkic v Yunseong Chung [293] | 6-3,6-4 | |
| Challenger - Zhangjiagang | 09/07 03:00 | 27 | [315] Yunseong Chung v Alexander Bublik [203] | 4-6,4-6 | |
| Challenger - Zhangjiagang | 09/06 02:00 | 26 | [176] Go Soeda v Yunseong Chung [315] | 5-7,6-3,2-6 | |
| Challenger - Zhangjiagang | 09/05 02:00 | 25 | [315] Yunseong Chung v Roman Safiullin [292] | 3-6,6-4,6-3 | |
| Challenger Gwangju | 08/14 01:00 | 25 | [312] Yunseong Chung v Benjamin Lock [474] | 4-6,6-4,3-6 | |
| Challenger - Lexington | 08/04 19:50 | 28 | [338] Yunseong Chung v Stefano Napolitano [233] | 5-7,3-6 | |
| Challenger - Lexington | 08/03 23:00 | 27 | [338] Yunseong Chung v Jay Clarke [175] | Retired | |
| Challenger - Lexington | 08/02 14:00 | 26 | Jeffrey John Wolf v Yunseong Chung | 3-6,7-6,5-7 |
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.