He is best known for his portrayal of obsessed police detective Mark McPherson in the noir mystery Laura (1944) and his critically acclaimed performance as World War II veteran Fred Derry returning home in The Best Years of Our Lives (1946).

[6] In 1938, Andrews was spotted in the play Oh Evening Star and Samuel Goldwyn (c.1879/1882-1974), signed the promising actor to a contract, but felt he needed time to develop experience.

His next film for Goldwyn was the Howard Hawks directed comedy Ball of Fire (1941), again teaming with Gary Cooper, with Andrews playing the villain, a gangster.

He was second lead to Tyrone Power in Crash Dive (1943) and then appeared as a lynching target in the 1943 film adaptation of The Ox-Bow Incident with Henry Fonda, giving a performance that Bosley Crowther of the New York Times called "heart-wringing," writing that Andrews "does much to make the picture a profoundly distressing tragedy.

One of his roles was as a detective infatuated with a presumed murder victim, played by Gene Tierney, in Laura (1944), produced at Fox and directed by Otto Preminger.

He co-starred with Jeanne Crain in the movie musical State Fair (1945), a huge hit, and was reunited with Preminger for the film noir Fallen Angel (1945).

Andrews made another war movie with Milestone, A Walk in the Sun (1945), then was loaned to Walter Wanger for a western, Canyon Passage (1946), directed by Jacques Tourneur and co-featuring Susan Hayward.

Upon release, the topical film about American society's problems in re-integrating military veterans after World War II outgrossed the longstanding box office success of Gone with the Wind (1939) in the U.S. and Britain.

In 1952, Andrews toured with his wife, Mary Todd, in The Glass Menagerie, and in 1958, he replaced Henry Fonda (his former co-star in The Oxbow Incident and Daisy Kenyon) on Broadway in Two for the Seesaw.

Although he had the lead in films such as Crack in the World (1965), Brainstorm (1965), and Town Tamer (1965), he was increasingly cast in supporting roles: Berlin, Appointment for the Spies (1965), The Loved One (1965), Battle of the Bulge (1965), and Johnny Reno (1966).

He occasionally played leads in low-budget films like The Frozen Dead (1966), The Cobra (1967) and Hot Rods to Hell (1967), however, by the late 1960s he had evolved into a character actor, as in The Ten Million Dollar Grab (1967), No Diamonds for Ursula (1967), and The Devil's Brigade (1968).

By the end of the decade, Andrews returned to television to play the leading role of college president Tom Boswell on the NBC daytime soap opera Bright Promise from its premiere on September 29, 1969, until March 1971.

[14] Andrews spent the 1970s in supporting roles of Hollywood films such as The Failing of Raymond (1971), Innocent Bystanders (1972), Airport 1975 (1974), A Shadow in the Streets (1975), The First 36 Hours of Dr. Durant (1975), Take a Hard Ride (1975), The Last Tycoon (1976), The Last Hurrah (1977), and Good Guys Wear Black (1978) He also appeared regularly on TV in such shows as Ironside, Get Christie Love!, Ellery Queen, The American Girls, The Hardy Boys, and The Love Boat.

[1] During the last years of his life, Andrews also suffered from senility / dementia factors of Alzheimer's disease, which was increasingly occurring in the elder American population with scientific research then in its infancy.