| Challenger de Chicago | 07/13 16:50 | 26 | [252] Yuta Shimizu v Yunseong Chung [313] | 6-3,5-7,6-3 | |
| Challenger de Chicago | 07/12 17:30 | 25 | [313] Yunseong Chung v Abdullah Shelbayh [235] | 6-3,6-4 | |
| Challenger de Chicago | 07/10 16:50 | 19 | Yunseong Chung v Thai-Son Kwiatkowski | 6-0,3-6,6-3 | |
| Challenger de Chicago | 07/09 17:20 | 14 | Yunseong Chung v Andrew Fenty | 7-5,6-2 | |
| Challenger de Bloomfield Hills | 07/04 15:00 | 19 | [313] Yunseong Chung v Ernesto Escobedo [399] | 4-6,3-6 | |
| Challenger de Bloomfield Hills | 07/03 16:25 | 14 | [313] Yunseong Chung v Strong Kirchheimer [387] | 6-4,7-6 | |
| ITF M25 Anseong | 06/24 02:55 | 28 | Yunseong Chung v Gerard Campana Lee | 2-6,6-2,3-6 | |
| ITF M25 Anseong | 06/23 02:00 | 27 | Yunseong Chung v Shunsuke Mitsui | 6-1,6-1 | |
| ITF M25 Anseong | 06/22 02:00 | 26 | Yunseong Chung v Dong Ju Kim | 3-6,6-1,7-5 | |
| ITF M25 Anseong | 06/21 05:50 | 25 | Yunseong Chung v Jae Myeong Lee | 6-2,6-2 | |
| ITF M25 Changwon | 06/15 02:30 | 26 | Yunseong Chung v Renta Tokuda | 6-7,1-6 | |
| ITF M25 Changwon | 06/14 01:00 | 25 | Yunseong Chung v Yeongseok Jeong | 6-2,6-2 | |
| ITF M25 Daegu | 06/09 00:50 | 27 | Yunseong Chung v Uisung Park | 6-7,3-6 | |
| ITF M25 Daegu | 06/08 00:50 | 26 | Yunseong Chung v Sanhui Shin | Retired | |
| ITF M25 Daegu | 06/07 03:55 | 25 | Yunseong Chung v Seokhyeon Chu | 6-3,6-1 | |
| Challenger de Busan | 05/11 06:40 | 26 | [328] Yunseong Chung v Gabriel Diallo [162] | 6-7,6-7 | |
| Challenger de Busan | 05/09 06:15 | 25 | [328] Yunseong Chung v Tung-Lin Wu [181] | 7-5,6-2 | |
| Challenger Gwangju | 05/05 04:45 | 26 | [363] Yunseong Chung v Jason Jung [338] | 6-3,3-6,4-6 | |
| Challenger Gwangju | 05/02 06:40 | 25 | [363] Yunseong Chung v Kaichi Uchida [150] | 7-6,6-3 | |
| Challenger de Seúl | 04/29 06:00 | 28 | [363] Yunseong Chung v Aleksandar Vukic [142] | 6-7,1-6 | |
| Challenger de Seúl | 04/28 04:00 | 27 | [141] Rinky Hijikata v Yunseong Chung [363] | 2-6,3-6 | |
| Challenger de Seúl | 04/27 04:00 | 26 | [363] Yunseong Chung v Jordan Thompson [91] | 6-4,6-3 | |
| Challenger de Seúl | 04/26 02:00 | 25 | [363] Yunseong Chung v Peter Gojowczyk [345] | 6-2,6-3 | |
| ITF M25 Jakarta | 04/20 03:55 | 26 | Yunseong Chung v Kasidit Samrej | Retired | |
| ITF M25 Jakarta | 04/19 04:00 | 25 | [357] Yunseong Chung v Fajing Sun [316] | 6-3,6-4 | |
| ITF M25 Jakarta | 04/13 02:30 | 26 | M Rifqi Fitriadi v Yunseong Chung | Retired | |
| ITF M25 Jakarta | 04/12 04:25 | 25 | Andrew Rogers v Yunseong Chung | 4-6,2-6 | |
| ITF M25 Kashiwa | 04/07 01:00 | 27 | [215] Yu Hsiou Hsu v Yunseong Chung [351] | 6-1,6-4 | |
| ITF M25 Kashiwa | 04/06 01:30 | 26 | Daisuke Sumizawa v Yunseong Chung | 2-6,2-6 | |
| ITF M25 Kashiwa | 04/04 01:00 | 25 | Takeru Yuzuki v Yunseong Chung | 2-6,2-6 |
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.