31 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Hampden | 1 | 36,382 | 33,025 | 1.26% | 2,108 | 17 | Township |
| Upper Allen | 2 | 25,304 | 23,265 | 1.67% | 1,910 | 13 | Township |
| Carlisle | 3 | 23,701 | 20,149 | 2.56% | 4,284 | 6 | Borough |
| East Pennsboro | 4 | 21,986 | 20,910 | 1.14% | 2,086 | 11 | Township |
| Lower Allen | 5 | 21,741 | 20,132 | 2.04% | 2,160 | 10 | Township |
| South Middleton | 6 | 18,952 | 16,172 | 3.81% | 389 | 49 | Township |
| North Middleton | 7 | 13,267 | 12,100 | 1.62% | 572 | 23 | Township |
| Mechanicsburg | 8 | 10,447 | 9,361 | 1.76% | 4,333 | 2 | Borough |
| Camp Hill | 9 | 8,288 | 8,117 | 0.35% | 3,900 | 2 | Borough |
| Middlesex | 10 | 7,979 | 7,033 | 3.37% | 311 | 26 | Township |
| New Cumberland | 11 | 7,677 | 7,520 | 0.34% | 4,583 | 2 | Borough |
| Monroe | 12 | 6,978 | 6,256 | 1.65% | 268 | 26 | Township |
| Plainfield | 13 | 6,297 | 6,244 | 0.32% | 254 | 25 | Township |
| West Pennsboro | 14 | 5,785 | 5,593 | 0.68% | 191 | 30 | Township |
| Shippensburg | 15 | 5,715 | 5,484 | 0.69% | 2,818 | 2 | Borough |
| Dickinson | 16 | 5,562 | 5,303 | 0.83% | 121 | 46 | Township |
| Lemoyne | 17 | 4,900 | 4,672 | 0.78% | 3,040 | 2 | Borough |
| Shippensburg | 18 | 4,351 | 4,286 | 0.28% | 1,754 | 2 | Township |
| Wormleysburg | 19 | 3,116 | 3,055 | 0.32% | 4,010 | 1 | Borough |
| North Newton | 20 | 2,655 | 2,557 | 0.8% | 117 | 23 | Township |
| Upper Frankford | 21 | 2,334 | 2,133 | 1.57% | 120 | 19 | Township |
| Mount Holly Springs | 22 | 2,037 | 1,998 | 0.34% | 1,499 | 1 | Borough |
| Lower Frankford | 23 | 1,914 | 1,755 | 1.92% | 130 | 15 | Township |
| Lower Mifflin | 24 | 1,806 | 1,756 | 0.44% | 76 | 24 | Township |
| Shiremanstown | 25 | 1,679 | 1,648 | 0.3% | 5,487 | 0 | Borough |
| Newville | 26 | 1,423 | 1,389 | 0.42% | 3,396 | 0 | Borough |
| South Newton | 27 | 1,408 | 1,371 | 0.57% | 124 | 11 | Township |
| Upper Mifflin | 28 | 1,383 | 1,317 | 0.51% | 64 | 22 | Township |
| Newburg | 29 | 365 | 350 | 0.83% | 1,973 | 0 | Borough |
| Cooke | 30 | 215 | 204 | 1.42% | 11 | 20 | Township |
| Newburg | 31 | 81 | 83 | 0% | 44 | 2 | Borough |
Hampden is the largest city in Cumberland County, with a population of 36,382.
Newburg is the smallest city in Cumberland County, with a population of 81.
There are 31 cities in Cumberland County, Pennsylvania.