41 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Robinson | 1 | 15,855 | 15,506 | 0.6% | 1,042 | 15 | Township |
| Indiana | 2 | 14,430 | 14,021 | 0.47% | 8,204 | 2 | Borough |
| Indiana | 3 | 7,506 | 7,245 | 0.91% | 427 | 18 | Township |
| Center | 4 | 4,374 | 4,384 | 0.02% | 109 | 40 | Township |
| Armagh | 5 | 4,067 | 4,018 | 0.17% | 44 | 93 | Township |
| Burrell | 6 | 3,466 | 3,480 | 0% | 145 | 24 | Township |
| Green | 7 | 3,410 | 3,412 | 0.09% | 65 | 53 | Township |
| Blairsville | 8 | 3,209 | 3,215 | -0.03% | 2,269 | 1 | Borough |
| Rayne | 9 | 2,778 | 2,783 | 0.11% | 59 | 47 | Township |
| Armstrong | 10 | 2,766 | 2,756 | 0.11% | 74 | 38 | Township |
| Cherryhill | 11 | 2,425 | 2,444 | -0.08% | 50 | 49 | Township |
| East Wheatfield | 12 | 2,127 | 2,134 | 0% | 78 | 27 | Township |
| West Wheatfield | 13 | 2,115 | 2,140 | -0.19% | 67 | 32 | Township |
| Conemaugh | 14 | 2,054 | 2,060 | 0% | 61 | 34 | Township |
| Pine | 15 | 1,856 | 1,856 | 0.05% | 60 | 31 | Township |
| South Mahoning | 16 | 1,817 | 1,818 | 0% | 64 | 29 | Township |
| Homer City | 17 | 1,723 | 1,729 | -0.06% | 3,121 | 1 | Borough |
| Brush Valley | 18 | 1,686 | 1,673 | 0.24% | 41 | 41 | Township |
| Young | 19 | 1,683 | 1,687 | 0% | 48 | 35 | Township |
| Robinson | 20 | 1,674 | 1,708 | -0.24% | 79 | 21 | Township |
| Canoe | 21 | 1,420 | 1,426 | -0.14% | 53 | 27 | Township |
| North Mahoning | 22 | 1,330 | 1,332 | 0.08% | 47 | 28 | Township |
| Clymer | 23 | 1,315 | 1,320 | -0.08% | 2,311 | 1 | Borough |
| West Mahoning | 24 | 1,307 | 1,322 | -0.31% | 45 | 29 | Township |
| Buffington | 25 | 1,229 | 1,227 | 0.16% | 40 | 31 | Township |
| Black Lick | 26 | 1,117 | 1,119 | 0% | 40 | 28 | Township |
| East Mahoning | 27 | 964 | 962 | 0% | 31 | 31 | Township |
| Banks | 28 | 899 | 901 | 0% | 28 | 32 | Township |
| West Lebanon | 29 | 857 | 833 | 0.71% | 2,214 | 0 | Township |
| Saltsburg | 30 | 767 | 770 | 0% | 3,705 | 0 | Borough |
| Grant | 31 | 634 | 635 | 0% | 24 | 27 | Township |
| Clymer | 32 | 607 | 620 | -0.16% | 18 | 34 | Township |
| Ernest | 33 | 420 | 419 | 0% | 1,826 | 0 | Borough |
| Marion Center | 34 | 405 | 404 | 0% | 545 | 1 | Borough |
| Creekside | 35 | 285 | 285 | 0% | 1,290 | 0 | Borough |
| Cherry Tree | 36 | 272 | 272 | 0% | 542 | 1 | Borough |
| Glen Campbell | 37 | 252 | 254 | 0% | 271 | 1 | Borough |
| Plumville | 38 | 251 | 254 | 0% | 506 | 0 | Borough |
| Armagh | 39 | 100 | 102 | 0% | 1,754 | 0 | Borough |
| Shelocta | 40 | 98 | 100 | 0% | 942 | 0 | Borough |
| Smicksburg | 41 | 56 | 56 | 0% | 384 | 0 | Borough |
Robinson is the largest city in Indiana County, with a population of 15,855.
Smicksburg is the smallest city in Indiana County, with a population of 56.
There are 41 cities in Indiana County, Pennsylvania.