John Colchin (dates unknown) was an English cricketer who played in first-class cricket for Kent during the 1740s. Believed to have been the brother of Robert Colchin, he is first recorded in a 1748 single wicket match. He played in two matches in 1749, first playing for Robert Colchin's XI against Stephen Dingate's XI at the Artillery Ground on Monday, 26 June 1749. This match was arranged by the London Cricket Club for one hundred guineas a side but the result is unknown. On Monday, 28 August 1749, he again played for his brother's team against Tom Faulkner's XI, the stake being sixty guineas a side and the result again unknown.
According to F. S. Ashley-Cooper, Colchin was convicted of felony at Maidstone Assizes in July 1762. He and one John Grigg were sentenced to seven years transportation.
As Colchin had established his reputation by 1748, he must have been active for some years previously and his career probably began earlier in the 1740s. Very few players were mentioned by name in contemporary reports and there are no other references to Colchin.