Xenia is a city in and the county seat of Greene County, Ohio, United States. Located in southwestern Ohio, it is 15 miles east of Dayton a…Xenia is a city in and the county seat of Greene County, Ohio, United States. Located in southwestern Ohio, it is 15 miles east of Dayton and is part of the Dayton metropolitan area as well as the Miami Valley region. As of the 2020 census, the city had a population of 25,441. The city's name comes from the Greek word Xenia, which means "hospitality".