The largest county in Alabama

There are two right answers. By land area it is Baldwin County; by population it is Jefferson County. Which one you want depends on what you meant by largest.

Largest by land area

Baldwin County

1,590 sq mi

3.1% of Alabama's land

Largest by population

Jefferson County

665,742 people

12.8% of Alabama's population

Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025. Retrieved 30 August 2026.

By land area

The ten largest counties of Alabama by land area. Land area excludes inland and coastal water.
RankNameLand areaPopulation
1Baldwin County1,590 sq mi267,761
2Tuscaloosa County1,321 sq mi241,368
3Clarke County1,238 sq mi22,014
4Mobile County1,229 sq mi411,658
5Jefferson County1,112 sq mi665,742
6Washington County1,080 sq mi14,822
7Jackson County1,078 sq mi54,281
8Covington County1,031 sq mi37,947
9Monroe County1,026 sq mi18,965
10Dallas County978.7 sq mi35,140

By population

The ten most populous counties of Alabama, from the Census Bureau's Vintage 2025 estimates.
RankNamePopulationDensity
1Jefferson County665,742599 per sq mi
2Madison County433,516541 per sq mi
3Mobile County411,658335 per sq mi
4Baldwin County267,761168 per sq mi
5Tuscaloosa County241,368183 per sq mi
6Shelby County238,552304 per sq mi
7Montgomery County225,891288 per sq mi
8Lee County189,881313 per sq mi
9Morgan County126,483218 per sq mi
10Limestone County122,928218 per sq mi

And the smallest

Smallest by land area

Etowah County

535.1 sq mi

Least populous

Greene County

7,067 people

More on Alabama

Rebuilt from source data 30 August 2026. How these figures are produced.