Washington County is a county in Illinois, United States, in the southwestern part of the state, an area locally known as “Little Egypt.” It had a population of 13,761 people at the 2020 census and covers 564 square miles (1,460 km2), of which 563 square miles is land and 1.3 square miles is water, centred near 38°21′N 89°25′W.
Nashville is the county seat, and its postal code is 62263. The county has 3 cities, 10 villages and a scatter of unincorporated communities across 16 civil townships. Washington County observes Central Time and its FIPS code is 17189.
Towns & Villages in Washington County
Washington County has three incorporated cities — Ashley, Centralia (its small northern slice) and Nashville, the seat — plus ten villages and roughly a dozen unincorporated communities that survive as crossroads, rail sidings or former mining camps. “CDP” below marks a census-designated place with no municipal government; “Unincorp.” marks a named community with neither.
| Place | Type | Pop. | ZIP |
|---|---|---|---|
| Nashville | City · seat | — | 62263 |
| Ashley | City | — | 62808 |
| Centralia | City | — | 62801 |
| Okawville | Village | — | 62271 |
| Hoyleton | Village | — | 62803 |
| Irvington | Village | — | 62848 |
| Richview | Village | — | 62877 |
| Addieville | Village | — | 62214 |
| Du Bois | Village | — | 62831 |
| Radom | Village | — | 62876 |
| Oakdale | Village | — | 62268 |
| New Minden | Village | — | — |
| Venedy | Village | — | — |
| Lively Grove | Unincorp. | — | — |
| Plum Hill | Unincorp. | — | — |
| Beaucoup | Unincorp. | — | — |
| Covington | Unincorp. | — | — |
| Elkton | Unincorp. | — | — |
| Clarmin | Unincorp. | — | — |
| Cordes | Unincorp. | — | — |
| Huegely | Unincorp. | — | — |
| Posen | Unincorp. | — | — |
| Pyramid | Unincorp. | — | — |
| Stone Church | Unincorp. | — | — |
| DuBois Center | Unincorp. | — | — |
| Johannisburg | Unincorp. | — | — |
| Frogtown | Unincorp. | — | — |
| Kempside | Unincorp. | — | — |
| Noltings | Unincorp. | — | — |
| Alda | Unincorp. | — | — |
| Biddleborn | Unincorp. | — | — |
| Caspars | Unincorp. | — | — |
| McKinley | Unincorp. | — | — |
Centralia straddles the Marion–Clinton–Washington county line; only its southern edge falls inside Washington County, and the city’s main post office and city government sit across the line in Marion County. DuBois Center, a Methodist retreat and outdoor-education center near the village of Du Bois, is a distinct place from the village itself despite the shared name.
ZIP Codes
- 62263 — Nashville
- 62271 — Okawville
- 62808 — Ashley
- 62803 — Hoyleton
- 62848 — Irvington
- 62877 — Richview
- 62214 — Addieville
- 62831 — Du Bois (also serves DuBois Center)
- 62876 — Radom
- 62268 — Oakdale
- 62801 — Centralia (post office based in neighboring Marion County)
New Minden and Venedy have no post office of their own; mail there is handled through the Okawville and Nashville ZIPs respectively.
Geography
Washington County sits in the till plains of southwestern Illinois, mostly flat to gently rolling farmland broken by wooded creek bottoms. The Kaskaskia River forms most of the county’s northern border, and Beaucoup Creek and the Little Crooked Creek drain the interior toward it. The county has six neighbors: Clinton County to the north, Marion County to the northeast, Jefferson County to the east, Perry County to the south, Randolph County to the southwest, and St. Clair County to the west. Only Marion, Jefferson and Perry counties currently have their own Towns & Villages page on this site; Clinton, Randolph and St. Clair counties do not yet.
Demographics
Washington County had 13,761 residents at the 2020 census, making it one of the smaller counties in southwestern Illinois. Nashville and Okawville are its two largest communities. The county is overwhelmingly rural — more than 99% of residents live outside any urban area — and median household income runs below the Illinois median of $80,306, typical for the state’s farm counties outside the St. Louis metro. Population density works out to roughly 24 people per square mile.
Economy & Local Life
Row-crop and livestock farming anchors the county’s economy, with corn and soybeans the dominant crops on the till-plain ground north and west of Nashville. Okawville is known regionally for the Original Springs Hotel, a mineral-spring resort dating to the 19th century. Nashville hosts Washington County Hospital and county government offices, and DuBois Center draws church and school groups from across southern Illinois for its retreat and camping programs. Despite lying just east of the St. Louis area, the county is not counted as part of the Metro-East and stays economically tied to the smaller cities of Centralia and Mount Vernon.
History
Washington County was organized on January 2, 1818, carved out of St. Clair County, and named for George Washington. Early settlement followed the Kaskaskia River and the timber along Beaucoup Creek. German and Polish immigrant communities took root in the 19th century around villages such as Okawville, Hoyleton and Radom — Radom itself is named for the city in Poland. Coal mining shaped the eastern part of the county in the early 20th century, with the Lively Grove and Plum Hill communities growing up around mine works that have since closed.
Getting There
Interstate 64 crosses the northern edge of the county near Okawville, and U.S. Route 51 runs north–south through Centralia and Richview. Illinois Routes 4, 13, 15, 127, 153, 157, 160 and 177 fill out the local network.
- Nashville — about 45 miles southeast of St. Louis, Missouri
- Centralia — roughly 12 miles northeast of Nashville via US-51
- Belleville — about 30 miles west of Nashville via I-64
- Mount Vernon — about 25 miles east of Nashville
The nearest commercial airport is St. Louis Lambert International Airport, about an hour’s drive west.
Frequently Asked Questions
Where is Washington County, Illinois?
It is in southwestern Illinois, about 45 miles southeast of St. Louis, in the region locally called “Little Egypt.”
What is the population of Washington County?
13,761 people, per the 2020 census.
How big is Washington County?
564 square miles (1,460 km2), of which 563 square miles is land.
What is the county seat of Washington County?
Nashville is the county seat.
How many towns are in Washington County?
Three cities (Ashley, Centralia and Nashville) and ten villages, plus a number of small unincorporated communities.
What ZIP codes are in Washington County?
Nashville is 62263; other towns include Okawville (62271), Ashley (62808), Hoyleton (62803), Irvington (62848), Richview (62877), Addieville (62214), Du Bois (62831), Radom (62876) and Oakdale (62268).
Why is Washington County called “Little Egypt”?
It sits in the southern Illinois region historically nicknamed Little Egypt, a name tied to the area’s Nile-like river bottoms and 19th-century grain trade with the flooded prairies farther north.
More counties in this state: Towns and villages in Illinois.