Buchanan is a town in Outagamie County, Wisconsin, United States. The population was 6,755 at the 2010 census. The unincorporated community of Darboy is located in the town. According to the United States Census Bureau, the town has a total area of 16.9 square miles, of which, 16.6 square miles of it is land and 0.3 square miles of it is water.