Put under contract by 20th Century Fox, Mature was paired with Betty Grable and other light leading ladies in a series of musicals which required little of his abilities. Despite his almost too-handsome looks, Mature proved a much better actor than many (including himself) believed. Working in period films and Westerns, where he was often cast as characters of mythic proportions, such as the tubercular Doc Holliday in John Ford's splendid "My Darling Clementine" (1946) and the wilderness scout in "The Last Frontier" (1956). He was equally fine in such standout films noir as Henry Hathaway's "Kiss of Death" (1947) and Robert Siodmak's "Cry of the City" (1948). Memorable as Samson to Hedy Lamarr's Delilah (1949), Mature offered a more credible performance in "The Robe" (1953) than his prestige (but over-the-top) co-star Richard Burton.
Mature "retired" from acting in 1961 but made occasional films, generally poking fun at his image as an untalented hunk, as in his very funny turn as a has-been movie star not unlike himself in Vittorio De Sica's "After the Fox" (1966) and in Bob Rafelson's "Head" (1968, as The Big Victor). His last screen appearance was appropriately enough as Samson's father in the TV remake of "Samson and Delilah" (ABC, 1984).