Note: As defined by the US Census Bureau, a city's official boundaries often extend miles beyond the city itself and may even cross county lines. As such, several thousand US cities officially exist in two or more counties (and therefore appear on multiple counties' lists of cities.)
City | Rank | 2024 Pop. | 2020 Pop. | Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Helena | 1 | 35,204 | 32,244 | 2.15% | 2,084 | 16.9 | City |
| Helena Valley Southeast | 2 | 9,565 | 8,546 | 1% | 446 | 21.5 | CDP |
| Helena Valley West Central | 3 | 8,260 | 8,042 | 0.33% | 313 | 26.4 | CDP |
| Helena Valley Northwest | 4 | 5,420 | 4,256 | 2.63% | 331 | 16.4 | CDP |
| Helena Valley Northeast | 5 | 4,453 | 3,519 | 2.39% | 84 | 53.2 | CDP |
| East Helena | 6 | 2,201 | 1,948 | 2.95% | 543 | 4.1 | City |
| Helena West Side | 7 | 1,583 | 1,656 | -0.25% | 104 | 15.3 | CDP |
| Lincoln | 8 | 1,004 | 1,017 | 0% | 57 | 17.5 | CDP |
| Unionville | 9 | 407 | 151 | 7.67% | 318 | 1.3 | CDP |
| York | 10 | 273 | 158 | 7.48% | 832 | 0.3 | CDP |
| Augusta | 11 | 199 | 238 | -3.86% | 216 | 0.9 | CDP |
| Rimini | 12 | 104 | 110 | 8.33% | 342 | 0.3 | CDP |
| Marysville | 13 | 70 | 71 | 7.69% | 141 | 0.5 | CDP |
| Canyon Creek | 14 | 69 | 71 | 7.81% | 94 | 0.7 | CDP |
| Craig | 15 | 46 | 16 | 9.52% | 154 | 0.3 | CDP |
| Gilman | 16 | 29 | 41 | 7.41% | 44 | 0.7 | CDP |
| Wolf Creek | 17 | 14 | 22 | 7.69% | 65 | 0.2 | CDP |
Note: City markers shown outside the county boundary mean that a part of the city extends into this county, but is primarily located in an adjacent county.
Helena is the largest city in Lewis and Clark County.
Wolf Creek is the smallest city in Lewis and Clark County.
There are 17 cities in Lewis and Clark County, Montana.