John Barnett Rambo (born 9 August, 1943 in Atlanta, TX) was an American athlete who competed mainly in the high jump.
Rambo competed for the United States in the 1964 Summer Olympics held in Tokyo, Japan in the high jump where he won the bronze medal.
While at Long Beach State, John Rambo won the 1964 NCAA high jump and later won the AAU indoor title in 1967 and 1969. After graduation he came close to making the Olympic team for a second time when he tied for fourth place at the 1968 Final Trials. In 1965, Rambo was drafted in the sixth round by the St. Louis Hawks of the NBA, but never actually played pro basketball.