She was born Dorothy Arlene Dodd on December 29, 1911 in Baxter, Iowa when her Little Rock, Arkansas parents were on a trip to Des Moines. Her father was a doctor who abandoned her and her mother before she was ten years old. Her mother suffered from tuberculosis and Dorothy was forced to support her. She went to New York at the age of fifteen, lied about her age, and joined the Ziegfeld Follies where she was eventually discovered by Darryl F. Zanuck, the head of Fox.

Zanuck brought her to Hollywood and shepherded her throughout most of her career. She worked for Warner Brothers, Paramount, and Universal. She typically played the conniving "other" woman and could not be cast as a "dumb blonde" because of her cerebral nature and demeanor. Good friends with Bette Davis, with whom she worked in Ex-Lady (1933), she worked with everyone from Humphrey Bogart and Errol Flynn to Barbara Stanwyck, and James Cagney.

She played famed Girl Friday Della Street in a couple of 1930s Perry Mason mystery film thrillers, starring Warren William and in one (The Case of the Velvet Claws (1936)), she married Mason, the only Della Street to do so. She played the female lead in İki Açıkgöz Bahriyede (1941) opposite Dick Powell but received lesser billing, which she claimed was a standard procedure practiced on her in recompense for her aloofness and refusal to go along with the Hollywood system. In fact, one reporter whom she rebuffed nicknamed her "Ice Bucket" and the reputation stuck.

She worked in almost sixty films between 1930 and 1942. She quit films and married second husband H. Brand Cooper, with whom she raised four children. She undertook and completed this phase of her life after age forty, giving birth to her last child at the age of forty-seven. She was, to say the least, a remarkable woman. She died in the family home from cancer on November 23, 1973, aged 61.