Xenia is a village in Clay County, Illinois, United States. The population was 391 at the 2010 census.
Xenia is located in southwestern Clay County at 38°38′15″N 88°38′15″W (38.6373694, -88.6374130). U.S. Route 50 passes to the north of the village, leading east 9 miles (14 km) to Flora and west 17 miles (27 km) to Salem.
According to the 2010 census, the village has a total area of 0.54 square miles (1.4 km2), all land.
The hunting camps of Kiffcart and Retherford were located in the southwest corner of Section 4. The buffalo trail was very wide in this area, therefore Lewis located in the northwest quarter of Section 3. Lewis remained there until 1830 when he sold his property to Dr. Davenport. A post office was established at the Davenport home with the help of John Pierce and John Gowdy, establishing the town of Xenia. The building of the railroad in 1854 expanded the town, and by 1870 the population had increased to 1,000. A sesquicentennial celebration was held in 1984.
As of the census of 2000, there were 407 people, 180 households, and 111 families residing in the village.