8 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Fairbury | 1 | 3,738 | 3,973 | -1.24% | 1,474 | 2.54 | City |
| Plymouth | 2 | 353 | 363 | -0.56% | 1,117 | 0.32 | Village |
| Diller | 3 | 262 | 249 | 1.16% | 621 | 0.42 | Village |
| Daykin | 4 | 150 | 155 | -0.66% | 915 | 0.16 | Village |
| Endicott | 5 | 108 | 113 | -0.92% | 236 | 0.46 | Village |
| Jansen | 6 | 95 | 100 | -1.04% | 304 | 0.31 | Village |
| Harbine | 7 | 50 | 54 | -1.96% | 476 | 0.10 | Village |
| Steele City | 8 | 47 | 49 | 0% | 202 | 0.23 | Village |
Fairbury is the largest city in Jefferson County, with a population of 3,738.
Steele City is the smallest city in Jefferson County.
There are 8 cities in Jefferson County, Nebraska.