John O'Brien (born 6 July 1932) is an Australian tennis player active during the 1950s and 1960s.

[2] In 1956 O'Brien appeared at the French Championships finishing in the first round, however he followed this up with a Round of 16 performance at Wimbledon where he was defeated by eventual champion Lew Hoad.

He returned to Roland Garros and Wimbledon in 1960, though he was eliminated in the Round of 128.

[2][3] O'Brien remained active into his eighties, and was as of December 2014[update] ranked tenth in the world for players over 80 years old.

This biographical article relating to Australian tennis is a stub.