The Davenport family was well known in theatrical circles. Her aunt, Fanny Davenport was considered one of the greatest stage actresses of her time and her father, Harry Davenport, was a Broadway star before later venturing into movies. Her mother, Alice Davenport, was a respected Broadway and film actress. With a background on the stage, Dorothy was in her early teens when she started playing bit parts in films. By the time she was 17, she was a star at Universal, where she would meet a young actor-assistant director-gopher-scenario writer named Wallace Reid. Called on to act with him in a film, she was frustrated by his apparent lack of acting ability on the first day, but was smitten with him on the third day of their work together. Dorothy was a horsewoman of distinction who had no regard for a man who couldn't stay in the saddle. When Wallace proved to be an excellent horseman, she was hooked.

After six months working on a job with another film company, Wallace returned to Universal and they married on October 13, 1913. The newlyweds continued to work. He directed and starred with Dorothy in two films a week for the next year. When Wallace left Universal Dorothy also left films, returning in 1916 to appear in a handful of them. In 1917 she gave birth to Wallace Reid Jr. and became a full-time mother and wife.

When Wallace Reid died from morphine addiction in 1923, Dorothy and Bessie Love made Human Wreckage (1923), a film that dealt with the dangers of narcotics. Dorothy would not return to the screen again until she directed and acted in The Red Kimono (1926). Dorothy later in life dabbled as a producer and a writer.