26 cities
| City | Rank | County | 2025 Pop. ↓ |
|---|---|---|---|
| Wilmington | 1 | New Castle County | 73,759 |
| Newark | 2 | New Castle County | 30,483 |
| Middletown | 3 | New Castle County | 26,259 |
| Bear | 4 | New Castle County | 23,995 |
| Glasgow | 5 | New Castle County | 15,681 |
| Brookside | 6 | New Castle County | 14,325 |
| Hockessin | 7 | New Castle County | 13,966 |
| Pike Creek Valley | 8 | New Castle County | 11,511 |
| Claymont | 9 | New Castle County | 10,676 |
| North Star | 10 | New Castle County | 8,468 |
| Wilmington Manor | 11 | New Castle County | 8,353 |
| Pike Creek | 12 | New Castle County | 6,744 |
| Edgemoor | 13 | New Castle County | 6,687 |
| Elsmere | 14 | New Castle County | 6,236 |
| New Castle | 15 | New Castle County | 5,758 |
| Townsend | 16 | New Castle County | 2,990 |
| Greenville | 17 | New Castle County | 2,948 |
| Delaware City | 18 | New Castle County | 1,945 |
| St. Georges | 19 | New Castle County | 1,630 |
| Bellefonte | 20 | New Castle County | 1,255 |
| Newport | 21 | New Castle County | 909 |
| Arden | 22 | New Castle County | 438 |
| Odessa | 23 | New Castle County | 366 |
| Ardentown | 24 | New Castle County | 259 |
| Ardencroft | 25 | New Castle County | 235 |
| Port Penn | 26 | New Castle County | 172 |
New Castle County is the county generally considered as North Delaware.