Ethel Shannon began her movie career as an extra in a moving picture. The part lasted several days, and before she left the studio, she was offered a lead with Bert Lytell sparking her film career.
Soon after Ethel had signed a contract with a movie studio in 1923 she was selected as one of the WAMPAS Baby Stars.
She appeared opposite Harry Carrey in The Texas Trail (1925) and the New York Times proclaimed her "one of the best leading women for this kind of photoplay." Despite good reviews Shannon left films in 1927 to marry publicist Joe Jackson.
Ethel's last film role was in the 1927 film Through Thick and Thin, although she had an uncredited role in the 1935 film Stars over Broadway.