Xenia ( ZEE-nee-ə) is a city in and the county seat of Greene County, Ohio, United States. The municipality is located in southwestern Ohio 15 miles (24 km) from Dayton and is part of the Dayton Metropolitan Statistical Area, as well as the Miami Valley region. The name comes from the Greek word Xenia (ξενία), which means "hospitality".
As of the 2010 census, the city had a population of 25,719. Xenia is the third-largest city by population in Greene County, behind Fairborn and Beavercreek. At the geographical center of the county, it was selected as the county seat and houses the County Courthouse, County Sheriff's Department, Jail, and other regional departments.
Xenia was founded in 1803, the year Ohio was admitted into the Union. In that year, European-American pioneer John Paul bought 2,000 acres (8.1 km2) of land from Thomas and Elizabeth Richardson of Hanover County, Virginia, for "1050 pounds current moneys of Virginia." Paul influenced county commissioners to locate the county seat on this land at the forks of the Shawnee creeks, stimulating development of the settlement here.
Joseph C. Vance was named to survey the site and lay out the town. The following year, he bought the town site of 257 acres (1.04 km2) from John Paul for $250.