COUNTY · IA

Sioux County, Iowa

Sioux County is a county in Iowa with FIPS code 19167 and an estimated population of 36,246 (Census 2023), 19th largest of 99 in the state.

County facts

Name
Sioux County
State
Iowa
Type
county
FIPS code
19167
State FIPS
19
Population (2023)
36,246
Change since 2020
+1.0%
State rank
19 of 99

Population is the Census Bureau’s Vintage 2023 estimate.

Other counties in Iowa

Questions

What is the FIPS code for Sioux County?

Sioux County, Iowa has the five-digit FIPS code 19167: 19 for the state and 167 for the county.

What state is Sioux County in?

Sioux County is in Iowa.

How do I know if an address is in this county?

Use the address lookup. ZIP codes and city names can cross county lines, so an address is the reliable check.

Sources: U.S. Census Bureau geographic reference files; Census Bureau Population Estimates, Vintage 2023. Last reviewed 2026-10-27.