County outline
Where Jefferson County is located
Area breakdown
Land accounts for 98.6% of Jefferson County’s measured area and water for 1.4%. Its combined area converts to 1,365.6 square kilometers or approximately 337,449 acres.
Green: land · blue: water
| Measurement | Square miles | Square kilometers | Acres |
|---|---|---|---|
| Land | 519.933 | 1,346.62 | 332,757.1 |
| Water | 7.331 | 18.987 | 4,691.8 |
| Total | 527.264 | 1,365.607 | 337,449 |
How Jefferson County compares
By original Census land area, Jefferson County ranks #46 of 82 in Mississippi and #2006 of 3,222 nationally. National rankings include the 50 states, District of Columbia, and Puerto Rico.
Its land area is 0.917 times the Mississippi county-equivalent median of 567 square miles. It accounts for 1.1% of the combined county land area in the state.
See the complete Mississippi ranking · What counts as a county equivalent?
Population and density of Jefferson County
The Census Bureau estimates that 6,825 people lived in Jefferson County on July 1, 2025. That ranks #2,745 of 3,222 county equivalents nationally and #79 of 82 in Mississippi. Since the April 1, 2020 estimates base of 7,259, the population has declined by 434 (−6%), compared with −0.2% for Mississippi as a whole.
With 519.9 square miles of land, that is 13 people per square mile (5.1 per km²), placing Jefferson County #2,532 nationally for density and #78 in Mississippi. The median county equivalent has 47 people per square mile; the Mississippi median is 43. Put another way, there are about 49 acres of land per resident.
| July 1 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
|---|---|---|---|---|---|---|
| Estimate | 7,248 | 7,140 | 7,086 | 6,979 | 6,887 | 6,825 |
| Change | — | −108 | −54 | −107 | −92 | −62 |
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 Jefferson County
1 incorporated place lies at least partly in Jefferson County. Together they are home to 1,315 people (19.3%); the other 5,510 (80.7%) live outside any incorporated place, in unincorporated communities and rural areas.
The largest is Fayette city, with 1,315 residents in the county.
Metropolitan area
Jefferson County is an outlying county of the Natchez, MS-LA Micropolitan Statistical Area. Its 3 county equivalents have 54,722 residents on 1,678 square miles of land; Jefferson County accounts for 31% of the land and 12.5% of the residents. By combined land it ranks #98 of 542 micropolitan areas, and #193 by population.
| County equivalent | Population 2025 | Land mi² |
|---|---|---|
| Adams County | 30,061 | 462.3 |
| Concordia ParishLouisiana | 17,836 | 695.7 |
| Jefferson County | 6,825 | 519.9 |
ZIP codes
7 ZIP Code Tabulation Areas have land in Jefferson County; 3 of them have most of their land inside the county, and the others mainly cover neighboring areas.
39069390963912039144396533966139668
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 Jefferson County
Jefferson County shares a land border with 6 county equivalents, including 1 in Louisiana. It has more land than 2 of them. The largest neighbor is Copiah County (777.3 mi²) and the smallest is Adams County (462.3 mi²). Together with its neighbors, Jefferson County forms a block of 4,000.5 mi² of land, of which it holds 13%.
| Bordering county equivalent | Land mi² | Size vs. Jefferson | Compare |
|---|---|---|---|
| Copiah County | 777.3 | 1.5× larger | Compare |
| Tensas ParishLouisiana | 603.3 | 1.2× larger | Compare |
| Lincoln County | 586.2 | 1.1× larger | Compare |
| Franklin County | 564 | 1.1× larger | Compare |
| Claiborne County | 487.4 | 1.1× smaller | Compare |
| Adams County | 462.3 | 1.1× smaller | Compare |
How big is Jefferson County compared with U.S. states?
Jefferson 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 times as much. Mississippi’s county land could hold about 90 areas the size of Jefferson County.
Another way to picture it: the same land area would fill a square about 22.8 miles (36.7 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 Jefferson County?
Jefferson County has more land than 1,216 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 Jefferson County at #2,080 nationally by total area, 74 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 1.4%, compared with a national county-equivalent median of 1.2% — 0.2 percentage points higher. 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 Jefferson County in the national ranking. They can be in different states and are not necessarily geographic neighbors.
| Land rank | County equivalent | Land mi² | Comparison |
|---|---|---|---|
| #2005 | Henderson County, Tennessee | 520 | Compare |
| #2006 | Jefferson County, Mississippi | 519.9 | This county |
| #2007 | Roscommon County, Michigan | 519.9 | 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 31.733633, -91.043878. 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: 1,346,620,542 m²; AWATER: 18,988,092 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 Jefferson County?
Jefferson County, Mississippi has 519.9 square miles (1,346.6 km²) of land and 7.331 square miles of water, for a total area of 527.3 square miles. It ranks #2006 of 3,222 U.S. county equivalents by land area.
Is Jefferson County the largest county in Mississippi?
No. Jefferson County ranks #46 of 82 in Mississippi by land area. The largest is Yazoo County, with 922.3 square miles of land.
What counties border Jefferson County?
Jefferson County shares a land border with Claiborne County, Franklin County, Adams County, Tensas Parish, Louisiana, Lincoln County, and Copiah County.
What is the population of Jefferson County?
The Census Bureau estimates Jefferson County had 6,825 residents on July 1, 2025, ranking #2,745 of 3,222 county equivalents. That is 13 people per square mile of land.
What is the county seat of Jefferson County?
The county seat of Jefferson County is Fayette.
Is Jefferson County part of a metropolitan area?
Yes. It is an outlying county of the Natchez, MS-LA Micropolitan Statistical Area, which has 3 county equivalents and 54,722 residents.
How many ZIP codes are in Jefferson County?
7 ZIP Code Tabulation Areas have land in Jefferson County, and 3 of them have most of their land inside the county. Census ZIP Code Tabulation Areas approximate USPS ZIP Code areas.
How does Jefferson County compare with U.S. states?
It has less land than every state. Rhode Island, the smallest, has 2 times as much land.
How many acres of land are in Jefferson County?
The land measurement converts to approximately 332,757 acres. Including water, total area is approximately 337,449 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.