Hal Mac Underwood (born November 9, 1945) is an American professional golfer.
Underwood played college golf at the University of Houston.
He played on two NCAA Championship teams (1966 and 1967), was an All-American in 1966 and 1967, and won several college tournaments.Underwood never won on the PGA Tour but finished runner-up to Gary Player in the 1971 Greater Jacksonville Open.
He had a little more success internationally, winning the 1975 Portuguese Open on the European Tour and the 1977 Queensland Open on the Australasian Tour.
Underwood was inducted into the Texas Golf Hall of Fame in 1991.