Eaton is a city in and the county seat of Preble County, Ohio, United States. The population was 8,407 at the 2010 census. It is part of the Dayton Metropolitan Statistical Area.
Founded in 1806 by William Bruce, it celebrated its bicentennial in the summer of 2006. It derives its name from Gen. William Eaton (1764–1811), the U.S. Consul at Tunis, who led a diverse army in a harrowing march from Egypt to Tripoli to meet the U.S. Naval forces. In addition to the city of Eaton and the county of Preble, various streets in Eaton (Decatur, Israel, Wadsworth and Somers) were also named in honor of various heroes of the Barbary Wars .
The town grew quickly following its establishment. In 1846, the town first had 1000 inhabitants. This growth was primarily derived from the town's location at the strategic junction of two turnpikes. In 1849, Eaton was the site of a cholera outbreak. About half of the inhabitants fled; of the remaining 600 people, 120 died.