Martin William Byrnes (born April 30, 1956) is an American former professional basketball player.

Born in Syracuse, New York, a 6'7" forward from Syracuse University, Byrnes played four seasons (1978–1981; 1982–1983) in the National Basketball Association (NBA) as a member of the Phoenix Suns, New Orleans Jazz, Los Angeles Lakers, Dallas Mavericks, and Indiana Pacers. He averaged 5.7 points per game in his NBA career and won an NBA Championship with the Lakers in 1980.

• Career statistics from NBA.com  and Basketball Reference