Initially billed by Paramount Pictures as Glenn Erickson, he began his screen career as a leading man in westerns. Erickson made his film debut in two 1933 band films with Betty Grable before starting a string of Buster Crabbe western films based on Zane Grey novels. Erickson took off four years to serve in the Navy during World War II as a combat photographer. Erickson served as an instructor, was shot down twice in the Pacific, and was twice wounded.
Erickson appeared in films such as College Holiday (1936), Conquest (1937), Ride a Crooked Mile (1938), The Snake Pit (1948),Sorry, Wrong Number (1948), Invaders from Mars (1953), On the Waterfront (1954), The Fastest Gun Alive (1956), Twilight for the Gods (1958), A Gathering of Eagles (1963), Roustabout (1964), and The Carpetbaggers (1964).
One of his more notable roles was as Deborah Kerr's macho husband in the stage and film versions of Tea and Sympathy. He also played the role of Pete, the vindictive boat engineer, in the 1951 screen remake of the famed musical Show Boat. His final film appearance was in Twilight's Last Gleaming (1977).
Erickson appeared frequently on television. Erickson was cast as Dr. Hillyer in "Consider Her Ways" (1964) and as Paul White in "The Monkey's Paw--A Retelling" (1965) on CBS's The Alfred Hitchcock Hour. He starred in The High Chaparral, as Big John Cannon, which aired on NBC from 1967 until 1971. He portrayed a rancher determined to establish a cattle empire in the Arizona Territory. He guest-starred in several TV series' includingRawhide, Bonanza, Gunsmoke, Marcus Welby, M.D., Medical Center, Cannon and The Rockford Files. His final role was in an episode of Fantasy Island in 1984.
Erickson was married to actress Frances Farmer from 1936 until 1942. The same day that his divorce from Farmer was finalized, June 12, 1942, he married actress Margaret Hayes – however, they divorced a month later. He married Ann Diamond in 1945. They had two children, William "Bill" Leif (born 1946) and Susan Irene (born 1950). His son Bill died in a car accident in 1971. Leif Erickson died of cancer in Pensacola, Florida on January 29, 1986, at the age of seventy-four.