| Challenger Little Rock | 2023/05/29 15:00 | Beibit Zhukayev v Colin Markes | 6-0,6-3 |
| Challenger Little Rock | 2023/05/28 17:35 | Colin Markes v Strong Kirchheimer | 5-7,7-6,7-6 |
| ITF M25 Pensacola | 2023/05/17 15:40 | Colin Markes v Jonah Braswell | 2-6,1-6 |
| ITF M15 Orange Park | 2023/05/05 18:10 | Matias Franco Descotte v Colin Markes | 6-4,6-7,6-0 |
| ITF M15 Orange Park | 2023/05/04 14:15 | Colin Markes v Rei Sakamoto | 5-7,6-4,6-2 |
| ITF M15 Orange Park | 2023/05/03 16:35 | Oren Vasser v Colin Markes | 2-6,1-6 |
| ITF M15 Vero Beach | 2023/04/27 14:40 | Jacob Brumm v Colin Markes | 7-6,6-1 |
| Challenger Tallahassee | 2023/04/17 15:50 | Martin Damm v Colin Markes | 6-4,6-3 |
| UTR Series NIT | 2023/05/19 18:30 | Nathan Cox v Constantinos Djakouris | 2-6,6-0,0-6 |
| UTR Series NIT | 2023/05/18 14:07 | Constantinos Djakouris v AJ Woodman | 6-1,0-0 |