Her Sister's Secret is a 1946 drama film directed by Edgar G. Ulmer and starring Nancy Coleman, Margaret Lindsay, Phillip Reed, and Regis Toomey. The film centers around a woman who falls in love with a soldier. Believing she has been abandoned, she gives her baby to her married sister. The picture was produced and distributed by Producers Releasing Corporation. The screenplay was by Anne Green from the novel Dark Angel by Gina Kaus.