Clarence Addison Dykstra (February 25, 1883 – May 6, 1950) was a U.S. administrator. He served as the first City Manager in the US in Cincinnati, Ohio after teaching government at the University of Chicago. He then became Chancellor of the University of Wisconsin (1937–1945) as well as Director of the Selective Service System between 1940 and 1941. He then became Provost of UCLA from 1945–1950. Dykstra was appointed by President Roosevelt to chair the 11-member National Defense Mediation Board, an effort to settle wartime disputes. He served from March 19 to July 1, 1941.