John Arthur Cottrill (born 18 November 1945) is an Australian former professional tennis player.

[1] Cottrill, a New South Wales junior hard court champion from Sydney, was a member of Australia's Davis Cup squad for a 1965 tie against Spain.

He took Roy Emerson to five sets in the semi-finals of the 1966 Australian Hard Court Championships.

[2] In 1967, his final year on tour, he was married to tennis player Joan Gibson and partnered with her to make the mixed doubles quarter-finals at Wimbledon.

They had a son born in 1969.