Marvin Barnes (born July 27, 1952, in Providence, Rhode Island) is a former basketball player.
A 6'8" forward from Providence College, Barnes (nicknamed "Bad News") played in the American Basketball Association from 1974 to 1976 and in the National Basketball Association from 1976 to 1980. He had his most success in the ABA, where he starred for the Spirits of St. Louis and was named Rookie of the Year for the 1974–75 season. He also shares the ABA record for most two-point field goals in a game, with 27. In 2005, the ABA 2000, the second incarnation of the ABA, named one of their divisions after him.