ZIP Codes of Washington County, KY

Population & People
Population & People
Total Population
11,623
Household Income
Household Income
Median Income
$62,612
Housing
Housing
Total Housing Units
4,977
Business & Economy
Business & Economy
Total Businesses
249
Employment
Employment
Employment Rate
57.04%
Education
Education
Bachelor's Degree+
20.26%
Source: U.S. Census ACS 2024 5-Year Estimates · rolled up across the 4 ZIPs in this county.
Data Last Updated: July 1, 2026
ZIP Codes:4 ZIP Codes (3 Standard, 1 PO Box, 0 Unique) [See All]
Area Code:859
Timezone:Eastern (GMT -05:00)
Local Time:11:53:41 PM
Population:11,623 [See All]
FIPS:21229
Land Area:271 sq mi
Water Area:4 sq mi
Coordinates:37.7620, -85.1822
Quick Link:
https://www.zip-codes.com/county/ky-washington.asp
Need Washington data in your app? Look up ZIP, county, and city data with a single API call.
Try Free
Kentucky's #90 most populous county
11,623 residents across 4 ZIPs — #90 of 120 Kentucky counties.

Standout ZIPs in this County


Most Populous
Springfield · 8,015 people
69.0% of county total
Highest Income
Springfield · $70,788 median
1.1× county average
Largest Land Area
Springfield · 190.9 sq mi
Spans the most ground
Fastest Growth
Willisburg · 14.6% (10-yr)
2,322 → 2,661 residents
Most Educated
Springfield · 24.2% bachelor's+
1,411 of 5,835 adults 25+

Things worth knowing about Washington County


11,623 residents live across 4 ZIPs covering 271 sq mi, served by 4 distinct USPS-recognized cities.

Population moved from 11,270 to 11,455 from 2014 to 2024 — a +1.6% change. 2 ZIPs gained residents, 1 lost.

The county's wealthiest ZIP 40069 (Springfield, $70,788 median) and poorest ZIP 40078 (Willisburg, $54,435) are 8.6 miles apart — a 1.3× income gap across local geography.

Median home values vary 1.2× across this county — from $158,600 in 40040 (Mackville) to $194,200 in 40069 (Springfield).

Density varies 33× across the county — from 40 people/sq mi in 40040 (Mackville) to 1,322 in 40061 (Saint Catharine).

Educational attainment ranges from 8.0% bachelor's+ in 40040 (Mackville) to 24.2% in 40069 (Springfield) — the breadth of educational profiles across the area.

Within Kentucky, this is the #90 most populous of 120 counties and ranks #44 for median household income .

Weighted by population, the typical household earns about $66,712 across the county — reflecting what a typical resident sees, not a simple ZIP average.

20.3% of adults age 25+ hold a bachelor's degree or higher (1,654 of 8,163 reporting).

3 Standard delivery, 1 PO Box only, 0 single-entity Unique ZIPs serve this county.

Stories about Washington County


Single-ZIP anchor

One ZIP holds the majority of this county's population — a sign of a county built around a single city or town.

Springfield

All ZIP Codes in Washington County


ZIPCityTypePopulationMedian IncomeArea (sq mi)10-yr Growth
40069SpringfieldStandard8,015$70,788190.9-5.4%
40078WillisburgStandard2,661$54,43560.714.6%
40040MackvilleStandard77919.664.7%
40061Saint CatharinePO Box1680.1

Adjacent & Nearby Counties