When she was a junior, she dropped out of Grew Seminary to study at the American Academy of Dramatic Arts.

[5] Johnson was signed to a contract with Metro-Goldwyn-Mayer by Cecil B. DeMille following a performance of The Silver Cord[4] at the Repertory Theater in Los Angeles, California.

Her film debut came in Dynamite (1929), written by Jeanie Macpherson and featuring Charles Bickford and Conrad Nagel.

She went on to appear in The Ship from Shanghai (1930), This Mad World (1930), Billy the Kid (1930), The Spoilers (1930) with Gary Cooper and Betty Compson, DeMille's Madam Satan (1930), Passion Flower (1930), Capra's American Madness (1932), Thirteen Women (1932), Of Human Bondage (which starred Leslie Howard and Bette Davis), Jalna (1935) and Mr. Lucky (1943).

Johnson was cast opposite Warner Baxter in a screen adaptation of Such Men Are Dangerous by Elinor Glyn.