Born in Bainbridge, Georgia, she attended a finishing school in Vermont and Syracuse University. At the age of 20, she became a chorus girl in New York City. In 1930, she signed with Paramount Studios, and made her official film debut in Fast and Loose.

During the rest of the 1930s she appeared in such films as The Smiling Lieutenant, Dr. Jekyll and Mr. Hyde, Trouble in Paradise, The Story of Temple Drake, Becky Sharp (for which she was nominated for the Academy Award for Best Actress), Barbary Coast, These Three, The Old Maid and Old Acquaintance.

Bette Davis later wrote of Hopkins' difficult manner during the production of their two films The Old Maid and Old Acquaintance, saying that Hopkins was a very talented actress, but her insecurity led her to constantly try to upstage her costars and "steal" their scenes. One of the scenes in The Old Maid which Davis admitted to enjoying very much was one where she slaps Hopkins hard. Davis attributed the demise of Hopkins' film career to her "temperamental" reputation in Hollywood.

Hopkins was one of the actresses who auditioned to portray Scarlett O'Hara in Gone with the Wind, having one advantage that no other leading lady had: she was a native Georgian; however she did not get the part, which went to Vivien Leigh, with Paulette Goddard close behind.

Late in life, Hopkins adopted a child, but didn't even return home on the same flight, leading many to question her sincerity and her maternal instincts.

She was also known for throwing wild parties that bordered on orgies and engaging in a bisexual lifestyle, as chronicled in The Sewing Circle, a book written (by Boze Hadleigh) about lesbians in Hollywood.

Hopkins died in New York, New York from a heart attack nine (9) days before her 70th birthday.

She has two stars on the Hollywood Walk of Fame: one for motion pictures at 1701 Vine Street, and one for television at 1708 Vine Street.