Kathleen Culman Ridder (October 2, 1922 – April 3, 2017) was an American philanthropist, educator, writer, and feminist. She graduated from University of Minnesota Duluth as a teacher, advocated for women's athletic programs at the University of Minnesota, and was a benefactor of Minnesota Golden Gophers women's ice hockey. She was active in Republican politics, supported the Equal Rights Amendment, and later turned to writing and philanthropy to help her causes. She was married to Robert Ridder, and is a namesake of the Ridder Arena.