Ruth Elfriede Hildner (November 1, 1919 - May 2, 1947) was an SS guard at several Nazi concentration camps during World War II.

Hildner was conscripted into camp service in July 1944 and on July 10, 1944 she arrived at Ravensbruck to be trained as a camp matron. Ruth, just twenty six years, entered Dachau in September 1944 as an Aufseherin. Next the Nazis sent her to a subcamp at Munich Agfa Camera Werke. Ruth eventually served in several subcamps, including Henningsdorf, Wittenberg and Haselhorst. In December 1944, Ruth arrived at Helmbrechts, a tiny subcamp of Flossenburg located near Hof, Germany. There she was well feared by the camps inmates, both Jews and non-Jews. In April 1945, the guards at the small camp evacuated the women in the face of he American Army. Ruth was one of several guards on the death march who took part in mistreatment and murder of several young girls with her rod. Ruth also accompanied the march into Zwodau, another subcamp of Flossenburg, located in Czechoslovakia. Several days later the march left there and headed into western Czechoslovakia. In very early May 1945, the SS men and female overseers fled the march site. Ruth then melted into the hoards of refugees. In April 1947, Czech. police arrested Ruth and put her in prison. On May 2, 1947 she was tried in a Prague military courtroom. That same day she was found guilty and hanged for war crimes. She was twenty-eight years old.