County outline
Where Knox County is located
Area breakdown
Land accounts for 99.6% of Knox County’s measured area and water for 0.4%. Its combined area converts to 1,004.3 square kilometers or approximately 248,159 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 386.33 | 1,000.59 | 247,251.2 |
| Water | 1.419 | 3.675 | 908.2 |
| Total | 387.749 | 1,004.265 | 248,159.4 |
How Knox County compares
By original Census land area, Knox County ranks #35 of 120 in Kentucky and #2582 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 1.263 times the Kentucky county-equivalent median of 306 square miles. It accounts for 1% of the combined county land area in the state.
See the complete Kentucky ranking · What counts as a county equivalent?
Population and density of Knox County
The Census Bureau estimates that 29,532 people lived in Knox County on July 1, 2025. That ranks #1,500 of 3,222 county equivalents nationally and #36 of 120 in Kentucky. Since the April 1, 2020 estimates base of 30,195, the population has declined by 663 (−2.2%), compared with +2.2% for Kentucky as a whole.
With 386.3 square miles of land, that is 76 people per square mile (30 per km²), placing Knox County #1,195 nationally for density and #47 in Kentucky. The median county equivalent has 47 people per square mile; the Kentucky median is 59. Put another way, there are about 8.4 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 30,186 | 30,019 | 29,721 | 29,696 | 29,652 | 29,532 |
| Change | — | −167 | −298 | −25 | −44 | −120 |
U.S. Census Bureau, Vintage 2025 population estimates. Estimates are revised each year and are not decennial census counts. Density divides the whole population by the whole county’s land area, so it describes an average, not how settlement is distributed within the county. Population sources and methods.
Cities and towns in Knox County
2 incorporated places lie at least partly in Knox County. Together they are home to 4,903 people (16.6%); the other 24,629 (83.4%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Barbourville city, with 3,064 residents in the county. By land, Corbin city is the largest at 7.964 mi² across all its counties.
| Incorporated place | Population 2025 | Since 2020 | Land mi² |
|---|---|---|---|
| Barbourville cityCounty seat | 3,064 | −5% | 2.658 |
| Corbin cityAlso in 2 other counties | 1,839 | −1.5% | 7.964 |
Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Knox County. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.
Metropolitan area
Knox County is a central county of the Corbin, KY Micropolitan Statistical Area. Its 4 county equivalents have 150,040 residents on 1,727.3 square miles of land; Knox County accounts for 22.4% of the land and 19.7% of the residents. By combined land it ranks #94 of 542 micropolitan areas, and #8 by population. It belongs to the Middlesborough-Corbin, KY Combined Statistical Area.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Laurel County | 63,746 | 433.7 |
| Whitley County | 37,297 | 437.9 |
| Knox County | 29,532 | 386.3 |
| Clay County | 19,465 | 469.3 |
ZIP codes
19 ZIP Code Tabulation Areas have land in Knox County; 15 of them have most of their land inside the county, and the others mainly cover neighboring areas.
40701407344075940763407714090340906409154092140923409354093940943409464094940953409824099540997
ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Lighter codes have less than half of their land in this county. Post-office-box and single-address ZIP Codes have no tabulation area.
Counties bordering Knox County
Knox County shares a land border with 4 county equivalents. It has more land than 1 of them. The largest neighbor is Clay County (469.3 mi²) and the smallest is Bell County (359 mi²). Together with its neighbors, Knox County forms a block of 2,086.3 mi² of land, of which it holds 18.5%.
| Bordering county equivalent | Land mi² | Size vs. Knox | Compare |
|---|---|---|---|
| Clay County | 469.3 | 1.2× larger | Compare |
| Whitley County | 437.9 | 1.1× larger | Compare |
| Laurel County | 433.7 | 1.1× larger | Compare |
| Bell County | 359 | 1.1× smaller | Compare |
How big is Knox County compared with U.S. states?
Knox County has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 2.7 times as much. Kentucky’s county land could hold about 102 areas the size of Knox County.
Another way to picture it: the same land area would fill a square about 19.7 miles (31.6 km) on each side. Real county shapes are rarely square, so this is a scale reference rather than a width or driving distance.
State figures are the sums of each state’s county-equivalent land measurements in the same Census release, so states and counties are compared on the same basis. Published state totals can differ slightly because of rounding. Compare all states · Counties bigger than entire states.
What stands out about Knox County?
Knox County has more land than 640 of the other 3,221 county equivalents in the dataset.
A median is the middle county-equivalent measurement, not the average of the largest and smallest. All three bars use the same linear scale. Very small areas may appear as a thin sliver; the labels retain their values.
Does including water change its rank?
Using land plus water places Knox County at #2,640 nationally by total area, 58 places farther from the top than its land rank. Other county equivalents gain more area when their water measurements are included.
Its water share is 0.4%, compared with a national county-equivalent median of 1.2% — 0.8 percentage points lower. This describes the statistical geography’s land/water mix, not flood exposure or developable land.
Closest positions in the national land ranking
These entries sit immediately beside Knox County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2581 | Marshall County, Illinois | 386.8 | Compare |
| #2582 | Knox County, Kentucky | 386.3 | This county |
| #2583 | Monroe County, Illinois | 385.3 | Compare |
Calculated from the same Census release as the area table. Total-area order uses original ALAND + AWATER; water shares and chart labels use published square miles. Calculation details.
Representative coordinates
The Census internal point is 36.888500, -83.855551. It represents a location inside the geography; it is not necessarily the centroid or the address of a courthouse.
Source and precision
U.S. Census Bureau, 2026 Gazetteer Files, Counties. Original ALAND: 1,000,591,234 m²; AWATER: 3,676,008 m². Rankings use ALAND; exact ties use ascending GEOID. Tables preserve Census-published square miles to three decimals, with conversions based on those values.
Common questions
How big is Knox County?
Knox County, Kentucky has 386.3 square miles (1,000.6 km²) of land and 1.419 square miles of water, for a total area of 387.7 square miles. It ranks #2582 of 3,222 U.S. county equivalents by land area.
Is Knox County the largest county in Kentucky?
No. Knox County ranks #35 of 120 in Kentucky by land area. The largest is Pike County, with 786.2 square miles of land.
What counties border Knox County?
Knox County shares a land border with Bell County, Whitley County, Clay County, and Laurel County.
What is the population of Knox County?
The Census Bureau estimates Knox County had 29,532 residents on July 1, 2025, ranking #1,500 of 3,222 county equivalents. That is 76 people per square mile of land.
What is the county seat of Knox County?
The county seat of Knox County is Barbourville.
What cities and towns are in Knox County?
Knox County has 2 incorporated places. The most populous are Barbourville city and Corbin city; 24,629 residents live outside any incorporated place.
Is Knox County part of a metropolitan area?
Yes. It is a central county of the Corbin, KY Micropolitan Statistical Area, which has 4 county equivalents and 150,040 residents.
How many ZIP codes are in Knox County?
19 ZIP Code Tabulation Areas have land in Knox County, and 15 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Knox County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2.7 times as much land.
How many acres of land are in Knox County?
The land measurement converts to approximately 247,251 acres. Including water, total area is approximately 248,159 acres. One square mile equals 640 acres.
Why might another source show a different area?
Check whether it reports land or total area, its Census vintage, and its rounding. Our guide explains how to reconcile county area figures.
Can this establish a property boundary?
No. Statistical measurements and generalized maps do not establish property lines. Consult the relevant local surveying or land-records authority.