Dorothy Emma Arzner (January 3, 1897 – October 1, 1979) was an American film director whose career in Hollywood spanned from the silent era of the 1920s into the early 1940s. From 1927 until her retirement from feature directing in 1943, Arzner was the only female director working in Hollywood. Additionally, she was one of a very few women able to establish a successful and long career in Hollywood as a film director until the 1970s. Arzner made a total of twenty films between 1927 and 1943 and launched the careers of a number of Hollywood actresses, including Katharine Hepburn, Rosalind Russell, and Lucille Ball. Additionally, Arzner was the first woman to join the Directors Guild of America and the first woman to direct a sound film.