| Challenger Canberra | 01/07 00:40 | 25 | [274] Yunseong Chung v Klein, Brydan [407] | 6-7,7-6,0-6 | |
| Challenger Noumea | 01/01 04:25 | 25 | [274] Yunseong Chung v Jurij Rodionov [217] | 4-6,1-6 | |
| Challenger Noumea | 12/31 00:30 | 24 | [262] Yunseong Chung v Brkic, Tomislav [309] | 6-3,6-2 | |
| Qatar F5, Simples | 12/11 12:00 | 25 | Yunseong Chung v Lozan, Kristian | Cancelled | |
| Open d'Australie Playoff Wilcard Australienne | 11/30 05:45 | 27 | Zhe Li v Yunseong Chung | 6-4,6-4 | |
| Open d'Australie Playoff Wilcard Australienne | 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 | |
| Liuzhou, Chine | 10/23 03:35 | 25 | [149] Miomir Kecmanovic v Yunseong Chung [282] | Retired | |
| Liuzhou, Chine | 10/22 04:45 | 54 | [282] Yunseong Chung v Emil Ruusuvuori [318] | 6-3,6-3 | |
| Liuzhou, Chine | 10/21 07:00 | 46 | Yunseong Chung v Hossam, Youssef | 7-5,6-3 | |
| Liuzhou, Chine | 10/20 08:20 | 45 | Yunseong Chung v Sidharth Rawat | 5-7,6-2,6-3 | |
| Ningbo, China | 10/19 03:00 | 27 | [291] Yunseong Chung v Gunneswaran, Prajnesh [170] | 2-6,1-6 | |
| Ningbo, China | 10/17 05:15 | 26 | [291] Yunseong Chung v Yosuke Watanuki [220] | 2-6,7-6,6-3 | |
| Ningbo, China | 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 Dubrivnyy, Artem | 3-6,5-7 | |
| Challenger Tashkent | 10/06 05:00 | 45 | Yunseong Chung v Korobeynikov, Grigoriy | 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 Gao, Xin [276] | 7-5,6-3 | |
| Challenger Kaohsiung | 09/15 12:10 | 45 | [293] Yunseong Chung v Prashanth, N. Vijay Sundar [231] | 7-5,6-2 | |
| Challenger Shanghai | 09/11 07:00 | 25 | [325] Aldin Setkic v Yunseong Chung [293] | 6-3,6-4 | |
| Zhangjiagang, China | 09/07 03:00 | 27 | [315] Yunseong Chung v Alexander Bublik [203] | 4-6,4-6 | |
| Zhangjiagang, China | 09/06 02:00 | 26 | [176] Soeda, Go v Yunseong Chung [315] | 5-7,6-3,2-6 | |
| Zhangjiagang, China | 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 | Wolf, Jeffrey John 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.