Stephen Tyng Mather High School (commonly known as simply Mather) is a public 4–year high school located in the West Ridge neighborhood on the north side of Chicago, Illinois, United States. Opened in 1959, Mather is operated by the Chicago Public Schools (CPS) district. Mather is named in honor of Stephen Mather, an industrialist and conservationist who became the first director of the National Park Service.