
Sioux County
- State:
- Iowa
- County Seat:
- Orange City
Sioux County's estimated 2025 population is 36,484 with a growth rate of 0.33% in the past year according to the most recent United States census data. Sioux County is the 18th largest county in Iowa. The 2010 population was 33,755 and has seen a growth of 8.08% since that time.