Key Club International is the oldest and largest service program for high school students. It is a student-led organization whose goal is to teach leadership through serving others. Key Club International is a part of the Kiwanis International group. Each local Key Club is, in turn, sponsored by a local Kiwanis club.

The organization was started by California State Commissioner of Schools Albert C. Olney, and vocational education teacher Frank C. Vincent, who together worked to establish the first Key Club at Sacramento High School in California, on May 7, 1925.