41 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Gettysburg | 1 | 9,032 | 7,104 | 4.45% | 5,441 | 2 | Borough |
| Parkville | 2 | 8,606 | 7,345 | 1.5% | 2,953 | 3 | CDP |
| Conewago | 3 | 8,145 | 7,872 | 0.74% | 782 | 10 | Township |
| Cumberland | 4 | 7,266 | 7,032 | 0.72% | 217 | 33 | Township |
| Straban | 5 | 5,003 | 4,857 | 0.64% | 146 | 34 | Township |
| Littlestown | 6 | 4,949 | 4,787 | 0.65% | 2,706 | 2 | Borough |
| Carroll Valley | 7 | 4,077 | 3,940 | 0.67% | 758 | 5 | Borough |
| Menallen | 8 | 3,842 | 3,698 | 0.84% | 90 | 43 | Township |
| McSherrystown | 9 | 3,181 | 3,079 | 0.63% | 6,213 | 1 | Borough |
| Union | 10 | 3,171 | 3,063 | 0.73% | 183 | 17 | Township |
| Lake Heritage | 11 | 3,080 | 2,788 | 3.91% | 1,661 | 2 | CDP |
| Germany | 12 | 2,941 | 2,842 | 0.75% | 272 | 11 | Township |
| Fairfield | 13 | 2,830 | 2,831 | 0.28% | 233 | 12 | Township |
| Latimore | 14 | 2,735 | 2,643 | 0.77% | 129 | 21 | Township |
| Lake Meade | 15 | 2,489 | 2,516 | -0.2% | 1,887 | 1 | CDP |
| Huntington | 16 | 2,473 | 2,391 | 0.77% | 99 | 25 | Township |
| Hamiltonban | 17 | 2,374 | 2,297 | 0.68% | 61 | 39 | Township |
| Pennville | 18 | 2,336 | 2,274 | 1.13% | 2,446 | 1 | CDP |
| Messiah College | 19 | 2,254 | 2,052 | 0.13% | 7,022 | 0 | CDP |
| Fairfield | 20 | 2,023 | 2,046 | -0.15% | 33 | 61 | Township |
| Hampton | 21 | 1,968 | 1,921 | 4.74% | 1,113 | 2 | CDP |
| New Oxford | 22 | 1,934 | 1,868 | 0.68% | 3,124 | 1 | Borough |
| Bonneauville | 23 | 1,817 | 1,759 | 0.61% | 1,881 | 1 | Borough |
| East Berlin | 24 | 1,593 | 1,542 | 0.63% | 2,266 | 1 | Borough |
| Biglerville | 25 | 1,263 | 1,226 | 0.56% | 1,940 | 1 | Borough |
| Abbottstown | 26 | 1,053 | 1,020 | 0.57% | 1,929 | 1 | Borough |
| Highland | 27 | 1,031 | 999 | 0.68% | 85 | 12 | Township |
| Fairfield | 28 | 987 | 1,009 | -0.1% | 51 | 19 | Township |
| Arendtsville | 29 | 897 | 867 | 0.67% | 1,120 | 1 | Borough |
| Bendersville | 30 | 765 | 737 | 0.66% | 1,692 | 0 | Borough |
| York Springs | 31 | 708 | 682 | 0.71% | 3,558 | 0 | Borough |
| Fairfield | 32 | 548 | 528 | 0.74% | 814 | 1 | Borough |
| McKnightstown | 33 | 515 | 501 | 3.83% | 356 | 1 | CDP |
| Heidlersburg | 34 | 386 | 596 | -5.16% | 552 | 1 | CDP |
| Hunterstown | 35 | 284 | 435 | -5.96% | 165 | 2 | CDP |
| Cashtown | 36 | 239 | 244 | -5.91% | 159 | 2 | CDP |
| Aspers | 37 | 205 | 193 | -4.65% | 221 | 1 | CDP |
| Idaville | 38 | 158 | 205 | -1.25% | 227 | 1 | CDP |
| Table Rock | 39 | 125 | 95 | 6.84% | 210 | 1 | CDP |
| Gardners | 40 | 84 | 57 | -4.55% | 182 | 0 | CDP |
| Orrtanna | 41 | 58 | 116 | -12.12% | 286 | 0 | CDP |
Gettysburg is the largest city in Adams County, with a population of 9,032.
Orrtanna is the smallest city in Adams County, with a population of 58.
There are 41 cities in Adams County, Pennsylvania.