[1] Hobart's Broadway stage debut was on September 17, 1923 at the Knickerbocker Theater, playing a young girl in Lullaby.

During her career in theater, she toured with Noël Coward in The Vortex and was cast opposite Helen Hayes in What Every Woman Knows.

Under contract to Universal, Hobart starred in A Lady Surrenders (1930), East of Borneo (1931), and Scandal for Sale (1932).

In 1931, she co-starred with Fredric March and Miriam Hopkins in Rouben Mamoulian's original film version of Dr. Jekyll and Mr. Hyde (1931).

In 1936, Surrealist artist Joseph Cornell, who bought a print of East of Borneo to screen at home, became smitten with the actress, and cut out nearly all the parts that did not include her.

[4] She believed that she first came to the attention of anti-Communist activists because of her commitment to improving working conditions for actors in Hollywood.

[8] In 1986, she recalled that "On my first three pictures, they worked me 18 hours a day and then complained because I was losing so much weight that they had to put stuff in my evening dress ...

Although Hobart was not a member of the Communist Party, she refused to cooperate, instead reading a prepared statement that concluded, "In a democracy no one should be forced or intimidated into a declaration of his principles.

[9] On October 9, 1932, she married William Mason Grosvenor, Jr., an executive in a chemical engineering firm.

On August 29, 2000, Hobart died at the Motion Picture and Television Country House and Hospital in Woodland Hills, California, aged 94,[2] from natural causes.