10 cities
| City | County | 2026 Pop. ↓ |
|---|---|---|
| Portsmouth | Rockingham County | 23,288 |
| Pelham | Hillsborough County | 15,019 |
| Plaistow | Rockingham County | 7,951 |
| Pembroke | Merrimack County | 7,667 |
| Plymouth | Grafton County | 6,647 |
| Peterborough | Hillsborough County | 6,471 |
| Pittsfield | Merrimack County | 4,164 |
| Plainfield | Sullivan County | 2,562 |
| Pittsburg | Coos County | 847 |
| Piermont | Grafton County | 765 |