She came to New York City at the age of 17. When she failed to land the job she wanted, Scott played for a time with a stock company in Omaha, Nebraska. Scott made her Broadway (Manhattan) stage debut as a half-breed in The Barrier by Rex Beach.
In 1926 she played the role of the mother in The Lullaby, performed at the Pasadena Playhouse. One critic commented that Scott was uniquely suited to play the part for which she was cast.
Her voice has all of the soft cadences of a woman loved and the shrill shriekings of a woman scorned. Other theatrical appearances of note are roles in Painted Faces, with comedian Joe E. Brown and The Copperhead, playing opposite Lionel Barrymore.
Scott preferred acting in motion pictures to her work on the stage. In Behold My Wife (1920) she played the leading feminine role as Lali, an American Indian maiden. The film was produced by Famous Players.
She believed youth was a necessity to succeed in films. As the camera is more stringent than the eye, youth is not as essential in theater. Scott told an interviewer that the majority of successful stage actresses are
middle-age and have a number of years of experience.
Scott was paired with Roscoe Arbuckle in the Paramount Pictures release, The Round Up (1920). She was contracted to George Medford Productions but made motion pictures for both Famous Players and
the Samuel Goldwyn Company.
An outdoor enthusiast, Scott was a frequent visitor to the Los Angeles, California Gun Club. She purchased a Thoroughbred sport model of the Lexington (automobile) in 1920.
She married a prominent New York physician. She shared an apartment for a time with her brother, Billie, in Hollywood.
Mabel Julienne Scott died in Los Angeles in 1976.