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.