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 |
|---|---|---|---|---|---|---|---|
| Kiskiminetas township | 1 | 4,478 | 4,603 | -0.84% | 110 | 40.7 | Township |
| Kittanning | 2 | 3,876 | 3,918 | -0.28% | 3,892 | 1.0 | Borough |
| East Franklin township | 3 | 3,706 | 3,809 | -1.01% | 120 | 30.9 | Township |
| Ford City | 4 | 2,756 | 2,854 | -0.9% | 4,273 | 0.6 | Borough |
| Cowanshannock township | 5 | 2,649 | 2,733 | -0.86% | 58 | 45.7 | Township |
| South Buffalo township | 6 | 2,640 | 2,707 | -0.83% | 97 | 27.3 | Township |
| North Buffalo township | 7 | 2,614 | 2,691 | -0.72% | 105 | 24.9 | Township |
| Parks township | 8 | 2,388 | 2,465 | -1% | 170 | 14.0 | Township |
| Gilpin township | 9 | 2,320 | 2,408 | -1.11% | 141 | 16.4 | Township |
| Leechburg | 10 | 2,072 | 2,146 | -0.91% | 4,720 | 0.4 | Borough |
| Plumcreek township | 11 | 2,039 | 2,105 | -0.97% | 48 | 42.4 | Township |
| Kittanning township | 12 | 1,972 | 2,028 | -0.8% | 64 | 30.7 | Township |
| Rayburn township | 13 | 1,716 | 1,772 | -0.98% | 145 | 11.8 | Township |
| Freeport | 14 | 1,677 | 1,739 | -0.95% | 1,320 | 1.3 | Borough |
| West Franklin township | 15 | 1,650 | 1,707 | -0.96% | 63 | 26.1 | Township |
| Mahoning township | 16 | 1,350 | 1,396 | -1.1% | 54 | 24.8 | Township |
| Sugarcreek township | 17 | 1,321 | 1,348 | -1.12% | 50 | 26.7 | Township |
| West Leechburg | 18 | 1,235 | 1,267 | -0.64% | 1,254 | 1.0 | Borough |
| North Apollo | 19 | 1,213 | 1,252 | -0.82% | 2,234 | 0.5 | Borough |
| West Kittanning | 20 | 1,148 | 1,190 | -0.95% | 2,676 | 0.4 | Borough |
| Rural Valley | 21 | 802 | 829 | -0.86% | 380 | 2.1 | Borough |
| Oklahoma | 22 | 768 | 788 | -0.65% | 1,265 | 0.6 | Borough |
| Parker | 23 | 676 | 698 | -0.88% | 707 | 1.0 | City |
| Worthington | 24 | 571 | 593 | -1.04% | 830 | 0.7 | Borough |
| Dayton | 25 | 534 | 552 | -0.93% | 1,420 | 0.4 | Borough |
| South Bethlehem | 26 | 471 | 486 | -0.84% | 3,099 | 0.2 | Borough |
| Manorville | 27 | 367 | 377 | -0.81% | 3,634 | 0.1 | Borough |
| Ford Cliff | 28 | 348 | 360 | -0.85% | 4,579 | 0.1 | Borough |
| Applewold | 29 | 327 | 338 | -0.91% | 6,957 | 0.0 | Borough |
| Elderton | 30 | 319 | 333 | -1.24% | 988 | 0.3 | Borough |
| Atwood | 31 | 106 | 110 | -0.94% | 51 | 2.1 | Borough |
| Cherry Valley | 32 | 56 | 59 | -1.75% | 20 | 2.8 | 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.
Kiskiminetas township is the largest city in Armstrong County.
Cherry Valley is the smallest city in Armstrong County.
There are 32 cities in Armstrong County, Pennsylvania.