St. Tammany Parish, Louisiana

St. Tammany Parish population, land area and income

St. Tammany Parish had 277,615 residents in the Census Vintage 2024 estimate, on 845.3 square miles of land. It ranks 4th of 64 in Louisiana by population and 16th by land area. That works out to 328.4 people per square mile, 3.4 times the US average of 96.3, and in the top quarter nationally.

The median county-equivalent in Louisiana has 31,591 residents, so St. Tammany Parish is 8.8 times that size.

Its SAIPE 2023 median household income of $78,484 is in the top quarter among 3,143 counties with an estimate.

How St. Tammany Parish's population changed since 2020

St. Tammany Parish gained 12,608 residents between the July 2020 and July 2024 estimates, a rise of 4.8%. That ranks 4th of 64 in Louisiana for growth. The median Louisiana county changed by -2.3%, and the state as a whole by -1.2%.

Since the April 2020 estimates base, St. Tammany Parish recorded 12,407 births and 11,893 deaths, a natural change of +514. Net international migration added +2,906 and net domestic migration, people moving to or from other US counties, came to +9,760. The largest single component was domestic migration, which added 9,760 people.

Where St. Tammany Parish is

The Census internal point of St. Tammany Parish is at 30.410000, -89.952000. It sits in UTM zone 16N. The map shades Louisiana's 64 county-equivalents by population change from 2020 to 2024, darker for faster growth, with St. Tammany Parish outlined. Dots are towns of 1,000+ people with residents in it.

Towns in St. Tammany Parish

5 incorporated places of 1,000+ people have residents in St. Tammany Parish, 58,498 people together, or 21% of the county. Each figure counts only the part of the town inside St. Tammany Parish; towns marked "part" extend into another county. The largest is Slidell with 28,440.

Counties bordering St. Tammany Parish

The Census 2024 county adjacency file lists 8 neighbors for St. Tammany Parish, including 2 across a state line. The most populous is Jefferson Parish, LA, with 427,253 residents. Distances run between Census internal points in a straight line.

• Jefferson Parish

  427,253 people

  63 mi S

• Orleans Parish

  362,701 people

  25 mi S

• Tangipahoa Parish

  139,823 people

  31 mi WNW

• MS

  Pearl River County, MS

  59,030 people

  33 mi NE

• MS

  Hancock County, MS

  46,492 people

  28 mi E

• Washington Parish

  45,090 people

  31 mi N

• St. Bernard Parish

  44,783 people

  53 mi SE

• St. John the Baptist Parish

  39,694 people

  37 mi WSW

Distance to Baton Rouge and the nearest big city

Baton Rouge is 73.6 miles W of St. Tammany Parish's internal point in a straight line. The nearest place of 100,000 or more is New Orleans, LA (population 362,701), 24.7 miles away. The nearest place of 10,000 or more is Mandeville, LA (population 12,973), 9.2 miles away.

St. Tammany Parish FIPS code

The FIPS code of St. Tammany Parish is 22103: state code 22 for Louisiana plus parish code 103. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $78,484.