[1] O'Neil was one of eleven children born to Judge Thomas Francis Patrick Noonan and his wife, Hannah Kelly, a Metropolitan Opera singer, in Bayonne, New Jersey.

[3] Convent-educated, she started her career in vaudeville, billed as Chotsie Noonan and known for her petite but curvaceous frame and curly brown hair.

She was teamed with Constance Bennett and Joan Crawford in the MGM film Sally, Irene and Mary (1925), directed by Edmund Goulding, which was "her big break.

Although her broad "Joisey" accent in early talkies like Jazz Heaven was unsuitable for most ingenue roles, Warner Bros. signed her to play streetwise girls in its feature films of 1929-30.

A showcase for O'Neil, the movie involves a brash chorus girl's effect upon a snobbish family when their son brings her home in order to research a novel.