29 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Augusta | 1 | 19,226 | 18,925 | 0.15% | 349 | 55 | City |
| Waterville | 2 | 17,358 | 16,694 | 0.06% | 1,283 | 14 | City |
| Winslow | 3 | 8,138 | 7,959 | 0.41% | 221 | 37 | Town |
| Oakland | 4 | 6,351 | 6,237 | 0% | 247 | 26 | Town |
| Gardiner | 5 | 6,160 | 5,976 | 0% | 393 | 16 | City |
| Winthrop | 6 | 6,103 | 6,136 | -0.68% | 196 | 31 | Town |
| Sidney | 7 | 5,002 | 4,665 | 0.99% | 118 | 42 | Town |
| Vassalboro | 8 | 4,697 | 4,533 | 0.47% | 106 | 44 | Town |
| China | 9 | 4,647 | 4,416 | 0.52% | 93 | 50 | Town |
| Monmouth | 10 | 4,290 | 4,087 | 0.63% | 126 | 34 | Town |
| Litchfield | 11 | 3,812 | 3,595 | 0.82% | 102 | 37 | Town |
| Belgrade | 12 | 3,707 | 3,249 | 2.69% | 86 | 43 | Town |
| West Gardiner | 13 | 3,694 | 3,674 | -0.08% | 150 | 25 | Town |
| Pittston | 14 | 3,503 | 2,893 | 2.91% | 109 | 32 | Town |
| Clinton | 15 | 3,383 | 3,371 | -0.06% | 77 | 44 | Town |
| Farmingdale | 16 | 3,035 | 2,998 | 0.1% | 270 | 11 | Town |
| Chelsea | 17 | 2,843 | 2,781 | 0.25% | 145 | 20 | Town |
| Benton | 18 | 2,824 | 2,722 | 0.32% | 99 | 28 | Town |
| Windsor | 19 | 2,778 | 2,639 | 0.76% | 80 | 35 | Town |
| Readfield | 20 | 2,769 | 2,604 | 1.1% | 95 | 29 | Town |
| Hallowell | 21 | 2,623 | 2,565 | 0.08% | 447 | 6 | City |
| Manchester | 22 | 2,493 | 2,457 | 0.04% | 117 | 21 | Town |
| Albion | 23 | 2,113 | 2,012 | 0.52% | 54 | 39 | Town |
| Mount Vernon | 24 | 1,854 | 1,728 | 1.09% | 49 | 38 | Town |
| Randolph | 25 | 1,783 | 1,744 | 0.28% | 835 | 2 | Town |
| Fayette | 26 | 1,293 | 1,165 | 1.41% | 44 | 29 | Town |
| Rome | 27 | 1,197 | 1,145 | 0.76% | 47 | 25 | Town |
| Wayne | 28 | 1,174 | 1,130 | 0.69% | 61 | 19 | Town |
| Vienna | 29 | 622 | 584 | 0.97% | 26 | 24 | Town |
Augusta is the largest city in Kennebec County, with a population of 19,226.
Vienna is the smallest city in Kennebec County, with a population of 622.
There are 29 cities in Kennebec County, Maine.