Darnell was married to pilot Merle Roy Robertson from 1957 to 1963. In 1957, she started drinking heavily and in November 1958 sank into a depression, but went into rehab, recovering for a while. In 1963, Darnell was granted a divorce from Robertson following an outburst in the courtroom, where she accused her third husband of fathering the baby of a Polish actress. She was promised alimony of $350 monthly until July 15, 1964, and then $250 until September 15, 1967.