11 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Topsham | 1 | 9,898 | 9,565 | 0.79% | 308 | 32 | Town |
| Bath | 2 | 8,830 | 8,765 | 0.15% | 968 | 9 | City |
| Bath | 3 | 8,774 | 8,765 | -0.49% | 962 | 9 | City |
| Richmond | 4 | 3,566 | 3,523 | -0.2% | 117 | 30 | Town |
| Woolwich | 5 | 3,239 | 3,072 | 0.4% | 92 | 35 | Town |
| Bowdoin | 6 | 3,206 | 3,139 | -0.09% | 74 | 43 | Town |
| Bowdoinham | 7 | 3,190 | 3,062 | 0% | 93 | 34 | Town |
| Phippsburg | 8 | 2,202 | 2,156 | -0.09% | 77 | 29 | Town |
| West Bath | 9 | 1,953 | 1,911 | 0.1% | 164 | 12 | Town |
| Georgetown | 10 | 1,091 | 1,057 | -0.09% | 59 | 19 | Town |
| Arrowsic | 11 | 504 | 480 | 0.8% | 65 | 8 | Town |
Topsham is the largest city in Sagadahoc County, with a population of 9,898.
Arrowsic is the smallest city in Sagadahoc County, with a population of 504.
There are 11 cities in Sagadahoc County, Maine.