10 cities
| City | County | 2025 Pop. ↓ |
|---|---|---|
| Portsmouth | Rockingham County | 22,827 |
| Pelham | Hillsborough County | 14,577 |
| Plaistow | Rockingham County | 7,764 |
| Pembroke | Merrimack County | 7,623 |
| Plymouth | Grafton County | 6,566 |
| Peterborough | Hillsborough County | 6,520 |
| Pittsfield | Merrimack County | 4,145 |
| Plainfield | Sullivan County | 2,548 |
| Pittsburg | Coos County | 843 |
| Piermont | Grafton County | 764 |