Jefferson County, Idaho Cities (2026)

6 cities

City
Rank
2026 Pop. ↓
2020 Pop.
Annual Change
Density
Area (mi²)
Type
Rigby15,9885,0732.62%2,4762 City
Menan27437150.68%7201 City
Ririe37396661.65%1,4211 City
Roberts46245003.48%1,9870 City
Lewisville54614161.77%6941 City
Mud Lake63793182.71%2,6690 City

Jefferson County Cities Summary

Largest City

Rigby is the largest city in Jefferson County, with a population of 5,988.

Smallest City

Mud Lake is the smallest city in Jefferson County, with a population of 379.

10 Largest Cities

There are 6 cities in Jefferson County, Idaho.

Location of Jefferson County