21 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| New Castle | 1 | 21,048 | 21,900 | -0.67% | 2,534 | 8 | City |
| Neshannock | 2 | 9,576 | 9,836 | -0.35% | 555 | 17 | Township |
| Ellwood City | 3 | 7,315 | 7,617 | -0.68% | 3,148 | 2 | Borough |
| Shenango | 4 | 6,946 | 7,127 | -0.37% | 284 | 24 | Township |
| Union | 5 | 4,826 | 4,986 | -0.43% | 507 | 10 | Township |
| North Beaver | 6 | 3,935 | 3,957 | -0.13% | 93 | 42 | Township |
| Pulaski | 7 | 3,040 | 3,095 | -0.03% | 99 | 31 | Township |
| Wilmington | 8 | 2,640 | 2,663 | -0.08% | 134 | 20 | Township |
| Mahoning | 9 | 2,611 | 2,703 | -0.46% | 109 | 24 | Township |
| Scott | 10 | 2,130 | 2,170 | -0.23% | 108 | 20 | Township |
| New Wilmington | 11 | 2,085 | 2,096 | -0.1% | 1,978 | 1 | Borough |
| Perry | 12 | 1,806 | 1,850 | -0.22% | 99 | 18 | Township |
| Pulaski | 13 | 1,247 | 1,291 | -0.4% | 1,715 | 1 | Township |
| Little Beaver | 14 | 1,182 | 1,225 | -0.51% | 58 | 20 | Township |
| Bessemer | 15 | 1,028 | 1,072 | -0.68% | 622 | 2 | Borough |
| Plain Grove | 16 | 748 | 776 | -0.53% | 43 | 17 | Township |
| South New Castle | 17 | 629 | 650 | -0.47% | 1,941 | 0 | Borough |
| Wampum | 18 | 535 | 556 | -0.56% | 543 | 1 | Borough |
| New Castle | 19 | 354 | 350 | 0.28% | 29 | 12 | Township |
| Enon Valley | 20 | 292 | 301 | -0.34% | 597 | 0 | Borough |
| Volant | 21 | 119 | 127 | -0.83% | 1,063 | 0 | Borough |
New Castle is the largest city in Lawrence County, with a population of 21,048.
Volant is the smallest city in Lawrence County, with a population of 119.
There are 21 cities in Lawrence County, Pennsylvania.