| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Williamsport | 1 | 27,327 | 27,719 | -0.21% | 3,113 | 9 | City |
| Montgomery | 2 | 26,192 | 25,884 | -0.07% | 2,464 | 11 | Township |
| Loyalsock | 3 | 11,359 | 11,584 | -0.3% | 538 | 21 | Township |
| South Williamsport | 4 | 6,099 | 6,251 | -0.41% | 3,212 | 2 | Borough |
| Montgomery | 5 | 5,837 | 5,738 | 0.24% | 87 | 67 | Township |
| Old Lycoming | 6 | 4,909 | 4,975 | -0.3% | 523 | 9 | Township |
| Montoursville | 7 | 4,613 | 4,744 | -0.47% | 1,270 | 4 | Borough |
| Jersey Shore | 8 | 4,030 | 4,138 | -0.44% | 3,480 | 1 | Borough |
| Muncy Creek | 9 | 3,565 | 3,575 | 0.06% | 178 | 20 | Township |
| Wolf | 10 | 3,072 | 3,105 | -0.39% | 157 | 20 | Township |
| Hepburn | 11 | 2,528 | 2,561 | -0.24% | 152 | 17 | Township |
| Muncy | 12 | 2,371 | 2,440 | -0.5% | 2,809 | 1 | Borough |
| Hughesville | 13 | 2,078 | 2,140 | -0.53% | 3,222 | 1 | Borough |
| Upper Fairfield | 14 | 1,793 | 1,814 | -0.28% | 100 | 18 | Township |
| Porter | 15 | 1,539 | 1,554 | 0% | 202 | 8 | Township |
| Montgomery | 16 | 1,530 | 1,575 | -0.52% | 2,797 | 1 | Borough |
| Lycoming | 17 | 1,480 | 1,502 | -0.4% | 97 | 15 | Township |
| Montgomery | 18 | 1,404 | 1,420 | -0.43% | 49 | 29 | Township |
| Muncy | 19 | 1,183 | 1,175 | -0.17% | 76 | 15 | Township |
| Duboistown | 20 | 1,180 | 1,196 | -0.34% | 2,138 | 1 | Borough |
| Moreland | 21 | 1,037 | 1,024 | 0.58% | 43 | 24 | Township |
| Piatt | 22 | 1,028 | 1,049 | -0.39% | 105 | 10 | Township |
| Cogan House | 23 | 929 | 933 | 0.11% | 13 | 70 | Township |
| Lewis | 24 | 852 | 862 | -0.23% | 23 | 37 | Township |
| Anthony | 25 | 846 | 865 | -0.35% | 54 | 16 | Township |
| Jordan | 26 | 829 | 845 | -0.48% | 40 | 21 | Township |
| Gamble | 27 | 784 | 777 | -0.13% | 17 | 45 | Township |
| Armstrong | 28 | 673 | 691 | -0.44% | 27 | 25 | Township |
| Nippenose | 29 | 652 | 661 | -0.15% | 59 | 11 | Township |
| Picture Rocks | 30 | 631 | 650 | -0.63% | 648 | 1 | Borough |
| Plunketts Creek | 31 | 584 | 595 | -0.34% | 11 | 54 | Township |
| Watson | 32 | 523 | 534 | -0.76% | 23 | 23 | Township |
| Bastress | 33 | 517 | 526 | 0.19% | 55 | 9 | Township |
| Brady | 34 | 489 | 501 | -0.41% | 55 | 9 | Township |
| McIntyre | 35 | 453 | 461 | -0.22% | 10 | 47 | Township |
| Cascade | 36 | 419 | 420 | 0% | 11 | 39 | Township |
| Cummings | 37 | 259 | 264 | -0.38% | 4.0 | 69 | Township |
| Pine | 38 | 255 | 260 | -0.39% | 3.0 | 75 | Township |
| McNett | 39 | 141 | 145 | -0.7% | 4.0 | 34 | Township |
| McHenry | 40 | 121 | 121 | 0.83% | 2.0 | 76 | Township |
| Brown | 41 | 90 | 92 | -1.1% | 1.0 | 73 | Township |
Williamsport is the largest city in Lycoming County, with a population of 27,327.
Brown is the smallest city in Lycoming County, with a population of 90.
There are 41 cities in Lycoming County, Pennsylvania.