In Alabama until age 12, Ann Steely attended high school and college in Oklahoma City, then worked as a stenographer to finance a trip to Hollywood, where luck soon favored her with a contract under Samuel Goldwyn. Recognizing her talent and appeal through a thick Southern accent, Goldwyn arranged rigorous voice and theatrical training at the American Academy of Dramatic Arts and elsewhere, gave her an Irish-sounding stage name and cast her in The Best Years of Our Lives. This film's success boded well for Cathy's career, and soon she was starred in the now-classic They Live by Night. However, her rise in films was checked when, at age 23, she married 48-year-old Robert Wyler, older brother of director William Wyler, with whom Goldwyn was feuding. The irate Goldwyn abruptly canceled her contract; thereafter she had no lasting association with any studio or producer. Her most memorable roles of the 1950s were in classic film-noir such as Detective Story, which typifies her sincere, believable performances as a sweet girl-next-door whose radiant inner beauty shone through an exterior not quite fitting the Hollywood glamor mold. Her last film was Ben-Hur, and she worked in TV into 1961. Belying Goldwyn's opinion, her marriage to Wyler proved happy though childless. Her death on their 22nd wedding anniversary followed a long struggle with cancer.
Most sources give her birth year as 1925, but some give 1923. Cathy's ancestry was Irish. Her parents separated when she was a child. Her chief leisure pursuit was writing poetry. Of Cathy's 17 films (all in starring or featured roles), 7 are film-noir or quasi-film-noir, making her a major contributor to the genre. One secondary source gives her cause of death as cerebral hemorrhage, but all primary sources indicate cancer. Sister-in-law of William Wyler, niece-in-law of Carl Laemmle, cousin-in-law of Carl Laemmle Jr. Aunt of Catherine Wyler and Judy Wyler. In 1947, she accepted the Oscar for "Best Actor in a Leading Role" on behalf of Fredric March, who was not present at the awards ceremony.