| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Topsham | 1 | 10,126 | 9,563 | 1.44% | 315 | 32 | Town |
| Bath | 2 | 8,850 | 8,772 | 0.17% | 970 | 9 | City |
| Richmond | 3 | 3,626 | 3,526 | 0.47% | 119 | 30 | Town |
| Woolwich | 4 | 3,331 | 3,075 | 1.34% | 95 | 35 | Town |
| Bowdoin | 5 | 3,266 | 3,139 | 0.37% | 75 | 43 | Town |
| Bowdoinham | 6 | 3,228 | 3,057 | 0.56% | 94 | 34 | Town |
| Phippsburg | 7 | 2,249 | 2,156 | 0.76% | 78 | 29 | Town |
| West Bath | 8 | 1,982 | 1,910 | 0.61% | 166 | 12 | Town |
| Georgetown | 9 | 1,105 | 1,057 | 0.36% | 59 | 19 | Town |
| Arrowsic | 10 | 501 | 476 | 0.4% | 65 | 8 | Town |
Topsham is the largest city in Sagadahoc County, with a population of 10,126.
Arrowsic is the smallest city in Sagadahoc County, with a population of 501.
There are 10 cities in Sagadahoc County, Maine.