15 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Barnstable Town | 1 | 49,577 | 48,872 | -0.26% | 827 | 60 | City |
| Falmouth | 2 | 33,267 | 32,541 | 0.06% | 755 | 44 | Town |
| Yarmouth | 3 | 25,150 | 24,990 | -0.12% | 1,041 | 24 | Town |
| Bourne | 4 | 20,580 | 19,604 | 0.18% | 506 | 41 | Town |
| Sandwich | 5 | 20,411 | 20,254 | -0.23% | 476 | 43 | Town |
| Mashpee | 6 | 15,476 | 15,068 | -0.02% | 662 | 23 | Town |
| Dennis | 7 | 14,662 | 14,676 | -0.68% | 712 | 21 | Town |
| Harwich | 8 | 13,558 | 13,430 | -0.23% | 649 | 21 | Town |
| Brewster | 9 | 10,485 | 10,318 | 0.18% | 457 | 23 | Town |
| Chatham | 10 | 6,715 | 6,593 | 0.03% | 415 | 16 | Town |
| Orleans | 11 | 6,619 | 6,306 | 1.02% | 467 | 14 | Town |
| Eastham | 12 | 5,822 | 5,746 | -0.02% | 417 | 14 | Town |
| Provincetown | 13 | 3,733 | 3,658 | 0.05% | 386 | 10 | Town |
| Wellfleet | 14 | 3,651 | 3,565 | 0.08% | 185 | 20 | Town |
| Truro | 15 | 2,486 | 2,439 | 0.04% | 119 | 21 | Town |
Barnstable Town is the largest city in Barnstable County, with a population of 49,577.
Truro is the smallest city in Barnstable County, with a population of 2,486.
There are 15 cities in Barnstable County, Massachusetts.