51 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Kiskiminetas township | 1 | 4,440 | 4,603 | -0.85% | 109 | 40.67 | Township |
| Kittanning | 2 | 3,866 | 3,918 | -0.26% | 3,882 | 1 | Borough |
| East Franklin township | 3 | 3,668 | 3,809 | -1.03% | 119 | 30.89 | Township |
| Ford City | 4 | 2,732 | 2,854 | -0.87% | 4,236 | 0.65 | Borough |
| Cowanshannock township | 5 | 2,626 | 2,733 | -0.87% | 58 | 45.66 | Township |
| South Buffalo township | 6 | 2,618 | 2,707 | -0.83% | 96 | 27.25 | Township |
| North Buffalo township | 7 | 2,595 | 2,691 | -0.73% | 104 | 24.85 | Township |
| Parks township | 8 | 2,364 | 2,465 | -1.01% | 168 | 14.04 | Township |
| Gilpin township | 9 | 2,294 | 2,408 | -1.12% | 139 | 16.45 | Township |
| Leechburg | 10 | 2,054 | 2,146 | -0.87% | 4,679 | 0.44 | Borough |
| Plumcreek township | 11 | 2,019 | 2,105 | -0.98% | 48 | 42.38 | Township |
| Kittanning township | 12 | 1,956 | 2,028 | -0.81% | 64 | 30.71 | Township |
| Orchard Hills | 13 | 1,912 | 2,390 | -0.16% | 485 | 3.95 | CDP |
| Rayburn township | 14 | 1,699 | 1,772 | -0.99% | 143 | 11.85 | Township |
| Freeport | 15 | 1,662 | 1,739 | -0.89% | 1,309 | 1.27 | Borough |
| West Franklin township | 16 | 1,634 | 1,707 | -0.97% | 63 | 26.09 | Township |
| West Hills | 17 | 1,464 | 1,330 | 0.9% | 449 | 3.26 | CDP |
| Lenape Heights | 18 | 1,359 | 1,202 | 0.89% | 1,779 | 0.76 | CDP |
| Mahoning township | 19 | 1,335 | 1,396 | -1.11% | 54 | 24.78 | Township |
| Sugarcreek township | 20 | 1,306 | 1,348 | -1.14% | 49 | 26.67 | Township |
| West Leechburg | 21 | 1,227 | 1,267 | -0.65% | 1,246 | 0.98 | Borough |
| North Apollo | 22 | 1,203 | 1,252 | -0.82% | 2,215 | 0.54 | Borough |
| West Kittanning | 23 | 1,138 | 1,190 | -0.87% | 2,653 | 0.43 | Borough |
| South Bend township | 24 | 968 | 1,010 | -0.82% | 43 | 22.54 | Township |
| Redbank township | 25 | 929 | 972 | -1.06% | 29 | 32.30 | Township |
| Rural Valley | 26 | 795 | 829 | -0.87% | 377 | 2.11 | Borough |
| Boggs township | 27 | 774 | 811 | -1.02% | 31 | 24.58 | Township |
| Oklahoma | 28 | 763 | 788 | -0.65% | 1,257 | 0.61 | Borough |
| Bradys Bend township | 29 | 750 | 783 | -1.06% | 59 | 12.61 | Township |
| Pleasant View | 30 | 721 | 634 | -0.55% | 1,252 | 0.58 | CDP |
| Parker | 31 | 671 | 698 | -0.74% | 702 | 0.96 | City |
| Burrell township | 32 | 632 | 656 | -0.78% | 29 | 21.46 | Township |
| Valley township | 33 | 621 | 653 | -1.11% | 42 | 14.74 | Township |
| Worthington | 34 | 566 | 593 | -0.88% | 823 | 0.69 | Borough |
| Parker township | 35 | 558 | 575 | -0.53% | 24 | 22.94 | Township |
| Dayton | 36 | 530 | 552 | -0.75% | 1,410 | 0.38 | Borough |
| South Bethlehem | 37 | 467 | 486 | -0.85% | 3,072 | 0.15 | Borough |
| Manorville | 38 | 365 | 377 | -0.54% | 3,614 | 0.10 | Borough |
| Perry township | 39 | 364 | 366 | 0.28% | 24 | 15.02 | Township |
| Ford Cliff | 40 | 345 | 360 | -0.86% | 4,539 | 0.08 | Borough |
| Pine township | 41 | 337 | 354 | -1.17% | 78 | 4.34 | Township |
| Cadogan township | 42 | 328 | 345 | -1.2% | 336 | 0.98 | Township |
| Applewold | 43 | 324 | 338 | -0.92% | 6,894 | 0.05 | Borough |
| Elderton | 44 | 316 | 333 | -0.94% | 978 | 0.32 | Borough |
| North Vandergrift | 45 | 315 | 247 | -2.48% | 802 | 0.39 | CDP |
| Templeton | 46 | 284 | 335 | -0.7% | 613 | 0.46 | CDP |
| Freeport township | 47 | 252 | 268 | -1.18% | 31 | 8.09 | Township |
| Kiskimere | 48 | 138 | 219 | 0% | 450 | 0.31 | CDP |
| Atwood | 49 | 105 | 110 | -0.94% | 50 | 2.09 | Borough |
| Hovey township | 50 | 69 | 74 | -1.43% | 37 | 1.84 | Township |
| Cherry Valley | 51 | 55 | 59 | -1.79% | 20 | 2.82 | Borough |
Kiskiminetas township is the largest city in Armstrong County, with a population of 4,440.
Cherry Valley is the smallest city in Armstrong County.
There are 51 cities in Armstrong County, Pennsylvania.