Dorothy Gish was born into a tumultuous family environment, where her father, James Lee Gish, was frequently absent due to his restless nature. Her mother, Mary Robinson McConnell, also known as Mary Gish, had turned to acting as a means of financial support for the family. As soon as Dorothy and her sister, Lillian Gish, were old enough, they became integral parts of the act, supplementing their income by posing for photographs and acting in melodramas of the time.
In 1912, the sisters met fellow child actress Mary Pickford, who secured them additional work with Biograph Pictures. Director D.W. Griffith was impressed by both girls and cast them in An Unseen Enemy (1912),their first film. Dorothy went on to star in over 100 two-reel films and features throughout her career.
She appeared in the highly successful Judith of Bethulia (1914) alongside Blanche Sweet, and made several films with her sister Lillian, including the extremely successful Hearts of the World (1918) and Orphans of the Storm (1921). In both films, Dorothy played French girls from different time periods, while Lillian tried her hand at directing, with the movie Remodeling Her Husband (1920),which starred Dorothy and actor James Rennie, whom Dorothy would later marry and divorce.
While Dorothy excelled in pantomime and light comedy, her popularity was always overshadowed by that of her sister Lillian, who was considered one of the silent screen's greatest stars. Dorothy would only make a handful of movies in the 1920s, and in Romola (1924) - a costume picture set in medieval Italy - she co-starred with Lillian once more. By 1926, Dorothy had relocated to England, where she starred as the title role in Nell Gwyn (1926). Her last silent film would be Madame Pompadour (1927).
In 1928, Dorothy retired from the screen, except for a few occasional roles, and went on to enjoy a long and successful career on the stage.