| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Barnstable Town | 1 | 50,134 | 48,863 | 0.07% | 837 | 60 | City |
| Falmouth | 2 | 33,309 | 32,551 | -0.16% | 756 | 44 | Town |
| Yarmouth | 3 | 25,107 | 24,997 | -0.47% | 1,039 | 24 | Town |
| Bourne | 4 | 20,759 | 19,584 | -0.06% | 510 | 41 | Town |
| Sandwich | 5 | 20,526 | 20,261 | -0.24% | 479 | 43 | Town |
| Mashpee | 6 | 15,376 | 15,068 | -0.59% | 657 | 23 | Town |
| Dennis | 7 | 14,870 | 14,680 | -0.24% | 722 | 21 | Town |
| Harwich | 8 | 13,590 | 13,421 | -0.33% | 651 | 21 | Town |
| Brewster | 9 | 10,411 | 10,318 | -0.44% | 454 | 23 | Town |
| Chatham | 10 | 6,755 | 6,597 | 0.04% | 418 | 16 | Town |
| Orleans | 11 | 6,523 | 6,314 | -0.02% | 461 | 14 | Town |
| Eastham | 12 | 5,831 | 5,749 | -0.22% | 417 | 14 | Town |
| Wellfleet | 13 | 3,747 | 3,564 | 1.08% | 189 | 20 | Town |
| Provincetown | 14 | 3,711 | 3,657 | -0.48% | 384 | 10 | Town |
| Truro | 15 | 2,478 | 2,431 | -0.2% | 118 | 21 | Town |
Barnstable Town is the largest city in Barnstable County, with a population of 50,134.
Truro is the smallest city in Barnstable County, with a population of 2,478.
There are 15 cities in Barnstable County, Massachusetts.