| ITF M25 Tamworth | 09/17 00:00 | - | Colin Sinclair vs Jesse Delaney | View |
| ITF M25 Tamworth | 09/12 00:00 | - | [297] Colin Sinclair v Al Shabab (UAE) [481] | 3-6,1-6 | |
| ITF M25 Tamworth | 09/11 06:30 | - | Colin Sinclair v Arjun Mehrotra | 6-2,4-6,7-6 | |
| ITF M25 Tamworth | 09/11 04:19 | - | Colin Sinclair v Asher Brownrigg | 6-2,6-3 | |
| ITF M15 Brisbane | 08/07 00:00 | - | Jeremy Jin v Colin Sinclair | 4-4 | |
| ITF M15 Brisbane | 08/06 00:00 | - | Scott Jones v Colin Sinclair | 6-7,5-7 | |
| UTR Pro Brisbane | 07/19 23:00 | 29 | Colin Sinclair v Noah Brownrigg | 6-3,6-3 | |
| UTR Pro Brisbane | 07/19 01:35 | 28 | Colin Sinclair v Ymerali Ibraimi | 7-6,6-2 | |
| UTR Pro Brisbane | 07/17 01:45 | - | Colin Sinclair v Stefan Storch | 6-2,6-2 | |
| UTR Pro Brisbane | 07/16 00:45 | - | Colin Sinclair v Nikolas Baker | 6-7,6-4,6-1 | |
| ITF M15 Tokyo | 07/11 01:00 | - | [295] Colin Sinclair v Kokoro Isomura [467] | 3-6,6-4,4-6 | |
| ITF M15 Tokyo | 07/10 03:24 | - | Colin Sinclair v Shu Matsuoka | 4-6,7-5,6-2 | |
| ITF M15 Tokyo | 07/08 05:18 | - | Colin Sinclair v Duckhee Lee | 4-6,6-2,3-0 |
Colin Sinclair (born December 19, 1994) is an American tennis player representing the Northern Mariana Islands.
He achieved a career best singles ranking of world No. 340 on 18 September 2023, and a career high doubles ranking of world No. 200 on 10 April 2023. He has won four doubles titles on the ATP Challenger Tour and eight doubles titles on the ITF Tour. Additionally, he has won three singles ITF titles.
He represents the Northern Mariana Islands in Davis Cup as part of the Pacific Oceania team since 2017 and has a career record of 18–5 (13–3 in singles, 5–2 in doubles) in the competition.