Jefferson County, Idaho Cities (2026)

City
Rank
2026 Pop. ↓
2020 Pop.
Annual Change
Density (/mi²)
Area (mi²)
Type
Rigby15,9095,0692.64%2,4442 City
Menan27247080.7%7021 City
Ririe37226691.55%1,3881 City
Roberts45924963.5%1,8850 City
Lewisville54444141.6%6691 City
Mud Lake63743182.75%2,6340 City

Jefferson County Cities Summary

Largest City

Rigby is the largest city in Jefferson County, with a population of 5,909.

Smallest City

Mud Lake is the smallest city in Jefferson County, with a population of 374.

10 Largest Cities

There are 6 cities in Jefferson County, Idaho.

Location of Jefferson County