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 |
|---|---|---|---|---|---|---|---|
| Johnstown | 1 | 17,809 | 18,372 | -0.79% | 3,012 | 5.9 | City |
| Somerset township | 2 | 11,376 | 12,066 | 0.02% | 177 | 64.2 | Township |
| Conemaugh township | 3 | 6,567 | 6,750 | -0.73% | 159 | 41.3 | Township |
| Somerset | 4 | 5,851 | 6,039 | -0.8% | 2,144 | 2.7 | Borough |
| Westmont | 5 | 4,788 | 4,936 | -0.77% | 2,054 | 2.3 | Borough |
| Windber | 6 | 3,803 | 3,931 | -0.83% | 1,932 | 2.0 | Borough |
| Jenner township | 7 | 3,565 | 3,700 | -1.03% | 55 | 64.6 | Township |
| Paint township | 8 | 2,993 | 3,039 | -0.53% | 93 | 32.3 | Township |
| Shade township | 9 | 2,377 | 2,450 | -0.88% | 35 | 68.7 | Township |
| Brothersvalley township | 10 | 2,329 | 2,372 | -0.56% | 37 | 62.6 | Township |
| Geistown | 11 | 2,284 | 2,358 | -0.83% | 2,151 | 1.1 | Borough |
| Elk Lick township | 12 | 2,195 | 2,258 | -1.04% | 38 | 57.1 | Township |
| Stonycreek township | 13 | 2,110 | 2,086 | 1.15% | 35 | 61.1 | Township |
| Summit township | 14 | 2,090 | 2,140 | -0.52% | 46 | 45.2 | Township |
| Meyersdale | 15 | 1,998 | 2,068 | -0.89% | 2,449 | 0.8 | Borough |
| Southmont | 16 | 1,980 | 2,044 | -0.8% | 1,882 | 1.1 | Borough |
| Berlin | 17 | 1,946 | 2,000 | -0.71% | 2,124 | 0.9 | Borough |
| Quemahoning township | 18 | 1,787 | 1,837 | -0.72% | 51 | 35.3 | Township |
| Ferndale | 19 | 1,495 | 1,546 | -0.86% | 3,833 | 0.4 | Borough |
| Milford township | 20 | 1,447 | 1,488 | -0.96% | 49 | 29.7 | Township |
| Lincoln township | 21 | 1,410 | 1,455 | -0.77% | 55 | 25.7 | Township |
| Jefferson township | 22 | 1,393 | 1,428 | -0.71% | 34 | 41.2 | Township |
| Boswell | 23 | 1,198 | 1,221 | -0.5% | 1,621 | 0.7 | Borough |
| Upper Turkeyfoot township | 24 | 1,031 | 1,063 | -0.96% | 27 | 38.6 | Township |
| Central City | 25 | 963 | 997 | -0.93% | 1,783 | 0.5 | Borough |
| Paint | 26 | 880 | 904 | -0.68% | 2,551 | 0.3 | Borough |
| Hyndman | 27 | 848 | 862 | -0.47% | 1,656 | 0.5 | Borough |
| Rockwood | 28 | 822 | 845 | -0.73% | 2,461 | 0.3 | Borough |
| Scalp Level | 29 | 722 | 746 | -0.82% | 1,079 | 0.7 | Borough |
| Confluence | 30 | 701 | 724 | -0.85% | 438 | 1.6 | Borough |
| Salisbury | 31 | 682 | 705 | -0.87% | 1,781 | 0.4 | Borough |
| Jennerstown | 32 | 662 | 678 | -0.6% | 344 | 1.9 | Borough |
| Hooversville | 33 | 604 | 627 | -0.98% | 989 | 0.6 | Borough |
| Garrett | 34 | 409 | 416 | -0.49% | 808 | 0.5 | Borough |
| Indian Lake | 35 | 388 | 390 | -0.26% | 109 | 3.6 | Borough |
| Schellsburg | 36 | 325 | 331 | -0.61% | 1,280 | 0.3 | Borough |
| Stoystown | 37 | 289 | 299 | -1.03% | 1,521 | 0.2 | Borough |
| Ursina | 38 | 233 | 241 | -0.85% | 259 | 0.9 | Borough |
| Addison | 39 | 214 | 166 | 5.94% | 393 | 0.5 | Borough |
| Wellersburg | 40 | 206 | 213 | -0.96% | 254 | 0.8 | Borough |
| Shanksville | 41 | 190 | 197 | -1.04% | 964 | 0.2 | Borough |
| Benson | 42 | 178 | 185 | -1.11% | 503 | 0.4 | Borough |
| New Baltimore | 43 | 133 | 137 | -0.75% | 383 | 0.3 | Borough |
| New Centerville | 44 | 122 | 126 | -0.81% | 859 | 0.1 | Borough |
| Casselman | 45 | 117 | 104 | 2.63% | 582 | 0.2 | Borough |
| Callimont | 46 | 52 | 54 | -1.89% | 12 | 4.4 | Borough |
| Seven Springs | 47 | 25 | 25 | 0% | 23 | 1.1 | Borough |
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.
Johnstown is the largest city in Somerset County.
Seven Springs is the smallest city in Somerset County.
There are 47 cities in Somerset County, Pennsylvania.