Though he also appeared on Return to Peyton Place, One Life to Live, and Another World, Gallison is most famous for his nearly two-decade run as Dr. Neil Curtis on the NBC soap opera Days of Our Lives.
Early in his career, he appeared in a 1962 episode of ABC and Warner Brothers' Lawman.
He abruptly left Days of Our Lives in 1991; his character was suddenly written off the show, and producers never released the reason for his firing.
He was born in Houston, Texas, and he later settled in Wilmington, North Carolina. His marriage to Melisa Evans began in 1980.
He and Melissa Reeves were both series regulars on Days of Our Lives.