34 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Augusta | 1 | 19,228 | 18,925 | 0.31% | 349 | 55 | City |
| Augusta | 2 | 19,197 | 18,925 | 0.15% | 348 | 55 | City |
| Waterville | 3 | 17,496 | 16,694 | 0.92% | 1,293 | 14 | City |
| Waterville | 4 | 17,347 | 16,694 | 0.06% | 1,282 | 14 | City |
| Winslow | 5 | 8,105 | 7,959 | 0.41% | 220 | 37 | Town |
| Oakland | 6 | 6,351 | 6,237 | 0% | 247 | 26 | Town |
| Gardiner | 7 | 6,206 | 5,976 | 0.75% | 396 | 16 | City |
| Gardiner | 8 | 6,160 | 5,976 | 0% | 393 | 16 | City |
| Winthrop | 9 | 6,145 | 6,136 | -0.68% | 197 | 31 | Town |
| Sidney | 10 | 4,953 | 4,665 | 1% | 117 | 42 | Town |
| Vassalboro | 11 | 4,675 | 4,533 | 0.47% | 106 | 44 | Town |
| China | 12 | 4,623 | 4,416 | 0.52% | 93 | 50 | Town |
| Monmouth | 13 | 4,263 | 4,087 | 0.64% | 125 | 34 | Town |
| Litchfield | 14 | 3,781 | 3,595 | 0.83% | 101 | 37 | Town |
| West Gardiner | 15 | 3,697 | 3,674 | -0.08% | 150 | 25 | Town |
| Belgrade | 16 | 3,610 | 3,249 | 2.76% | 83 | 43 | Town |
| Pittston | 17 | 3,404 | 2,893 | 3% | 106 | 32 | Town |
| Clinton | 18 | 3,385 | 3,371 | -0.06% | 77 | 44 | Town |
| Farmingdale | 19 | 3,032 | 2,998 | 0.1% | 270 | 11 | Town |
| Chelsea | 20 | 2,836 | 2,781 | 0.25% | 145 | 20 | Town |
| Benton | 21 | 2,815 | 2,722 | 0.32% | 99 | 28 | Town |
| Windsor | 22 | 2,757 | 2,639 | 0.77% | 80 | 35 | Town |
| Readfield | 23 | 2,739 | 2,604 | 1.11% | 94 | 29 | Town |
| Hallowell | 24 | 2,632 | 2,565 | 0.5% | 449 | 6 | City |
| Hallowell | 25 | 2,621 | 2,565 | 0.08% | 447 | 6 | City |
| Manchester | 26 | 2,492 | 2,457 | 0.04% | 117 | 21 | Town |
| Farmingdale | 27 | 2,338 | 2,451 | 1.08% | 984 | 2 | CDP |
| Albion | 28 | 2,102 | 2,012 | 0.53% | 54 | 39 | Town |
| Mount Vernon | 29 | 1,834 | 1,728 | 1.1% | 48 | 38 | Town |
| Randolph | 30 | 1,778 | 1,744 | 0.28% | 833 | 2 | Town |
| Fayette | 31 | 1,275 | 1,165 | 1.43% | 44 | 29 | Town |
| Rome | 32 | 1,188 | 1,145 | 0.76% | 47 | 25 | Town |
| Wayne | 33 | 1,166 | 1,130 | 0.69% | 61 | 19 | Town |
| Vienna | 34 | 616 | 584 | 0.98% | 25 | 24 | Town |
Augusta is the largest city in Kennebec County, with a population of 19,228.
Vienna is the smallest city in Kennebec County, with a population of 616.
There are 34 cities in Kennebec County, Maine.