Jefferson Parish area

Population and density of Jefferson Parish

The Census Bureau estimates that 431,398 people lived in Jefferson Parish on July 1, 2025. That ranks #178 of 3,222 county equivalents nationally and #2 of 64 in Louisiana. Since the April 1, 2020 estimates base of 440,741, the population has declined by 9,343 (−2.1%), compared with −0.9% for Louisiana as a whole.

With 300.9 square miles of land, that is 1,434 people per square mile (554 per km²), placing Jefferson Parish #125 nationally for density and #2 in Louisiana. The median county equivalent has 47 people per square mile; the Louisiana median is 48. Put another way, there are about 0.446 acres of land per resident.

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 Parish

6 incorporated places lie at least partly in Jefferson Parish. Together they are home to 102,599 people (23.8%); the other 328,799 (76.2%) live outside any incorporated place, in unincorporated communities and rural areas.

The largest is Kenner city, with 65,136 residents in the county. The county seat, Gretna city, has 17,360 residents. Among places with at least 1,000 residents in 2020, Jean Lafitte town grew fastest since then (+2.8%).

Population: U.S. Census Bureau Vintage 2025 subcounty estimates, counting only the part of each place inside Jefferson Parish. Land: 2026 Census Gazetteer, for the whole place even where it extends into other counties. How communities are listed.

Metropolitan area

Jefferson Parish is a central county of the New Orleans-Metairie, LA Metropolitan Statistical Area. Its 7 county equivalents have 970,849 residents on 2,358.6 square miles of land; Jefferson Parish accounts for 12.8% of the land and 44.4% of the residents. By combined land it ranks #139 of 393 metropolitan areas, and #60 by population. It belongs to the New Orleans-Metairie-Slidell, LA-MS Combined Statistical Area.

ZIP codes

17 ZIP Code Tabulation Areas have land in Jefferson Parish, and each lies mostly inside the county.

7000170002700037000570006700367005370056700587006270065700677007270094701217012370358

ZIP Code Tabulation Areas are the Census Bureau’s approximations of USPS ZIP Code service areas, from the 2020 Census relationship files. Post-office-box and single-address ZIP Codes have no tabulation area.

Counties bordering Jefferson Parish

Jefferson Parish shares a land border with 6 county equivalents. It has more land than 3 of them. The largest neighbor is Lafourche Parish (1,069.7 mi²) and the smallest is Orleans Parish (169.6 mi²). Together with its neighbors, Jefferson Parish forms a block of 3,658.3 mi² of land, of which it holds 8.2%.

How big is Jefferson Parish compared with U.S. states?

Jefferson Parish has less land than any of the 50 states. Rhode Island, the smallest state by land area, has 1,033.9 mi², about 3.4 times as much. Louisiana’s county land could hold about 144 areas the size of Jefferson Parish.

Another way to picture it: the same land area would fill a square about 17.3 miles (27.9 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 Parish?

Jefferson Parish has more land than 413 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 Parish at #1,602 nationally by total area, 1,207 places closer to the top than its land rank. The water assigned to this geography moves it ahead of some county equivalents with more land.

Its water share is 53.1%, compared with a national county-equivalent median of 1.2% — 52 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 Parish in the national ranking. They can be in different states and are not necessarily geographic neighbors.

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.