11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Topsham town | 1 | 9,781 | 9,565 | 0.15% | 304 | 32.18 | Town |
| Bath city | 2 | 8,942 | 8,764 | 0.55% | 980 | 9.12 | City |
| Bath | 3 | 8,897 | 8,764 | 0.3% | 976 | 9.12 | City |
| Richmond town | 4 | 3,566 | 3,526 | -0.08% | 117 | 30.43 | Town |
| Woolwich town | 5 | 3,270 | 3,076 | 0.93% | 93 | 35.06 | Town |
| Bowdoinham town | 6 | 3,231 | 3,060 | 0.72% | 94 | 34.43 | Town |
| Bowdoin town | 7 | 3,216 | 3,137 | 0.09% | 74 | 43.46 | Town |
| Phippsburg town | 8 | 2,221 | 2,155 | 0.36% | 77 | 28.76 | Town |
| West Bath town | 9 | 1,963 | 1,913 | 0.31% | 165 | 11.90 | Town |
| Georgetown town | 10 | 1,103 | 1,057 | 0.55% | 59 | 18.59 | Town |
| Arrowsic town | 11 | 502 | 479 | 0.8% | 65 | 7.75 | Town |
Topsham town is the largest city in Sagadahoc County, with a population of 9,781.
Arrowsic town is the smallest city in Sagadahoc County.
There are 11 cities in Sagadahoc County, Maine.