[2] Sebastian was born and raised in Birmingham, Alabama, the daughter of Lycurgus (Lawrence) Robert and Stella Armstrong Sabiston.

[citation needed] Before appearing in films, Sebastian performed onstage in the musical revue, George White's Scandals.

She co-starred with Joan Crawford and Anita Page in a popular series of MGM romantic dramas, including Our Dancing Daughters (1928) and Our Blushing Brides (1930).

[3] MGM released Sebastian in 1930; her last film for the studio was a short subject starring the young Jack Benny.

Her most familiar appearance in sound films is probably in Allez Oop (1934), a short comedy produced by Educational Pictures that reunited her with Buster Keaton.

[10] On November 7, 1938, Sebastian was found guilty of drunk driving in a Beverly Hills, California Justice Court.

[12] On April 8, 1957, Sebastian died of cancer at the Motion Picture & Television Country House and Hospital in Woodland Hills, California.