Patsy De Forest (born Helen May Lanagan; May 1, 1894 – August 1, 1966) was an American actress of the silent cinema era who performed on the stage since childhood before acting in films.

De Forest acted in over eighty films from 1912 to 1920, with over thirty appearances each in 1915 and in 1916.

She worked with several production companies including Lubin Manufacturing Company, Vitagraph Studios and Fox Film Corporation.

She acted in several comedies directed by Lawrence Semon of Vitagraph in the mid-1910s.

[3] De Forest's last film appearance was in Sunset Sprague, a 1920 Western in which she was the female lead.