44 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kiskiminetas | 1 | 4,466 | 4,608 | -0.69% | 110 | 41 | Township |
| Kittanning | 2 | 3,920 | 3,919 | 0% | 3,936 | 1 | Borough |
| East Franklin | 3 | 3,687 | 3,810 | -0.78% | 119 | 31 | Township |
| Ford City | 4 | 2,739 | 2,859 | -0.87% | 4,247 | 1 | Borough |
| South Buffalo | 5 | 2,648 | 2,711 | -0.45% | 97 | 27 | Township |
| Cowanshannock | 6 | 2,640 | 2,727 | -0.53% | 58 | 46 | Township |
| North Buffalo | 7 | 2,594 | 2,691 | -0.77% | 104 | 25 | Township |
| Parks | 8 | 2,377 | 2,468 | -0.79% | 169 | 14 | Township |
| Gilpin | 9 | 2,322 | 2,408 | -0.64% | 141 | 16 | Township |
| Leechburg | 10 | 2,057 | 2,145 | -0.87% | 4,686 | 0 | Borough |
| Plumcreek | 11 | 2,020 | 2,105 | -0.88% | 48 | 42 | Township |
| Kittanning | 12 | 1,982 | 2,027 | -0.15% | 65 | 31 | Township |
| Rayburn | 13 | 1,721 | 1,786 | -0.69% | 145 | 12 | Township |
| Freeport | 14 | 1,662 | 1,735 | -0.89% | 1,309 | 1 | Borough |
| West Franklin | 15 | 1,639 | 1,705 | -0.79% | 63 | 26 | Township |
| Mahoning | 16 | 1,341 | 1,397 | -0.96% | 54 | 25 | Township |
| Sugarcreek | 17 | 1,315 | 1,347 | -0.75% | 49 | 27 | Township |
| West Leechburg | 18 | 1,238 | 1,268 | -0.48% | 1,257 | 1 | Borough |
| North Apollo | 19 | 1,205 | 1,253 | -0.82% | 2,219 | 1 | Borough |
| West Kittanning | 20 | 1,143 | 1,192 | -0.87% | 2,664 | 0 | Borough |
| South Bend | 21 | 970 | 1,010 | -0.82% | 43 | 23 | Township |
| Redbank | 22 | 929 | 970 | -0.96% | 29 | 32 | Township |
| Rural Valley | 23 | 794 | 826 | -0.87% | 376 | 2 | Borough |
| Boggs | 24 | 773 | 812 | -1.02% | 31 | 25 | Township |
| Oklahoma | 25 | 764 | 788 | -0.65% | 1,259 | 1 | Borough |
| Bradys Bend | 26 | 752 | 782 | -0.79% | 60 | 13 | Township |
| Parker | 27 | 672 | 699 | -0.88% | 703 | 1 | City |
| Valley | 28 | 627 | 654 | -0.79% | 43 | 15 | Township |
| Burrell | 29 | 626 | 653 | -1.11% | 29 | 21 | Township |
| Worthington | 30 | 567 | 592 | -0.87% | 824 | 1 | Borough |
| Parker | 31 | 554 | 574 | -0.89% | 24 | 23 | Township |
| Dayton | 32 | 526 | 550 | -0.94% | 1,399 | 0 | Borough |
| South Bethlehem | 33 | 469 | 487 | -0.85% | 3,086 | 0 | Borough |
| Manorville | 34 | 364 | 376 | -0.82% | 3,604 | 0 | Borough |
| Perry | 35 | 357 | 367 | -0.83% | 24 | 15 | Township |
| Ford Cliff | 36 | 346 | 361 | -0.86% | 4,553 | 0 | Borough |
| Pine | 37 | 338 | 351 | -0.59% | 78 | 4 | Township |
| Applewold | 38 | 321 | 338 | -1.23% | 6,830 | 0 | Borough |
| Cadogan | 39 | 319 | 333 | -0.93% | 327 | 1 | Township |
| Elderton | 40 | 316 | 333 | -1.25% | 978 | 0 | Borough |
| Freeport | 41 | 252 | 267 | -1.56% | 31 | 8 | Township |
| Atwood | 42 | 105 | 110 | -0.94% | 50 | 2 | Borough |
| Hovey | 43 | 71 | 74 | 0% | 39 | 2 | Township |
| Cherry Valley | 44 | 56 | 59 | -1.75% | 20 | 3 | Borough |
Kiskiminetas is the largest city in Armstrong County, with a population of 4,466.
Cherry Valley is the smallest city in Armstrong County, with a population of 56.
There are 44 cities in Armstrong County, Pennsylvania.