Wholesome blonde actor who played decorative romantic leads opposite comedians Bob Hope and Danny Kaye in several Sam Goldwyn Technicolor romps of the 1940s including "The Princess and the Pirate" (1944) and "Wonder Man" (1945). Goldwyn also tried her in his acclaimed, Oscar-winning study of the difficulties of veterans' postwar readjustment, "The Best Years of Our Lives" (1946), in which she showed a likeable toughness and ordinariness rather than the usual peaches and cream appeal. Mayo was later in a few creditable "straight" roles including, most memorably, a pair of fine, rough-edged films for director Raoul Walsh, "White Heat" and "Colorado Territory" (both 1949), which suggested a greater acting potential than had been seen to that point.
Through the 1950s, though, Mayo toplined a series of harmless but middling films from every conceivable genre, lending her Technicolor prettiness and doing her professional best until her stardom petered out rather abruptly at the end of the decade. Her better films of the 1950s included "The Flame and the Arrow" (1950), "Great Day in the Morning" (1956) and "Westbound" (1959). She later appeared in slightly over half a dozen features from the 60s through the 90s. Some roles were "guest star" spots but she also played some leads and prominent supporting roles; unfortunately, films such as "Castle of Evil" (1966), "French Quarter" (1978) and "Evils Spirits" (1991) were routine low-budget fare at best and sometimes considerably worse. Mayo was married to actor Michael O'Shea from 1947 to 1973.