| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Brockton | 1 | 106,078 | 105,481 | -0.05% | 4,972 | 21 | City |
| Plymouth | 2 | 68,758 | 61,017 | 1.34% | 713 | 96 | Town |
| Bridgewater Town | 3 | 29,267 | 26,761 | -0.14% | 1,074 | 27 | City |
| Marshfield | 4 | 27,489 | 25,796 | 2.47% | 960 | 29 | Town |
| Middleborough | 5 | 25,312 | 24,263 | 0.65% | 367 | 69 | Town |
| Hingham | 6 | 24,449 | 24,256 | -0.13% | 1,101 | 22 | Town |
| Wareham | 7 | 23,735 | 23,275 | 0.19% | 663 | 36 | Town |
| Scituate | 8 | 19,646 | 19,069 | -0.08% | 1,141 | 17 | Town |
| Pembroke | 9 | 18,471 | 18,342 | -0.11% | 848 | 22 | Town |
| Rockland | 10 | 17,941 | 17,772 | -0.04% | 1,789 | 10 | Town |
| Abington | 11 | 17,126 | 17,052 | -0.09% | 1,719 | 10 | Town |
| Duxbury | 12 | 16,540 | 16,081 | 0.25% | 698 | 24 | Town |
| Whitman | 13 | 15,538 | 15,124 | 0.08% | 2,241 | 7 | Town |
| Hanover | 14 | 14,989 | 14,819 | 0.12% | 965 | 16 | Town |
| East Bridgewater | 15 | 14,619 | 14,431 | 0.12% | 848 | 17 | Town |
| Kingston | 16 | 14,578 | 13,717 | 0.21% | 782 | 19 | Town |
| Lakeville | 17 | 12,545 | 11,537 | 0.93% | 424 | 30 | Town |
| Carver | 18 | 12,046 | 11,633 | 0.54% | 323 | 37 | Town |
| Norwell | 19 | 11,551 | 11,342 | 0.04% | 552 | 21 | Town |
| Hanson | 20 | 11,092 | 10,624 | 1.51% | 739 | 15 | Town |
| Hull | 21 | 10,276 | 10,068 | 0.1% | 3,578 | 3 | Town |
| West Bridgewater | 22 | 7,922 | 7,709 | 0.64% | 517 | 15 | Town |
| Halifax | 23 | 7,850 | 7,746 | 0.06% | 491 | 16 | Town |
| Mattapoisett | 24 | 6,868 | 6,509 | 0.54% | 396 | 17 | Town |
| Rochester | 25 | 5,950 | 5,722 | -0.1% | 177 | 34 | Town |
| Marion | 26 | 5,368 | 5,339 | 0.04% | 380 | 14 | Town |
| Plympton | 27 | 2,991 | 2,928 | 0.2% | 204 | 15 | Town |
Brockton is the largest city in Plymouth County, with a population of 106,078.
Plympton is the smallest city in Plymouth County, with a population of 2,991.
There are 27 cities in Plymouth County, Massachusetts.