John Eaton, Jr. (December 5, 1829 – February 9, 1906) was an American educator who served as the U.S. Commissioner of Education and a Union Army colonel during the American Civil War. On March 12, 1866, the United States Senate confirmed his January 13, 1866 nomination for appointment to the grade of brevet brigadier general of volunteers to rank from March 13, 1865.