27 cities
| City | Rank | County | 2025 Pop. ↓ |
|---|---|---|---|
| Milford | 1 | Sussex County | 14,771 |
| Seaford | 2 | Sussex County | 9,194 |
| Georgetown | 3 | Sussex County | 8,324 |
| Millsboro | 4 | Sussex County | 8,094 |
| Laurel | 5 | Sussex County | 4,519 |
| Milton | 6 | Sussex County | 3,882 |
| Lewes | 7 | Sussex County | 3,797 |
| Selbyville | 8 | Sussex County | 3,379 |
| Long Neck | 9 | Sussex County | 3,234 |
| Ocean View | 10 | Sussex County | 3,113 |
| Bridgeville | 11 | Sussex County | 2,992 |
| Delmar | 12 | Sussex County | 2,337 |
| Millville | 13 | Sussex County | 2,170 |
| Lincoln | 14 | Sussex County | 1,799 |
| Blades | 15 | Sussex County | 1,367 |
| Rehoboth Beach | 16 | Sussex County | 1,292 |
| Greenwood | 17 | Sussex County | 1,155 |
| Bethany Beach | 18 | Sussex County | 1,114 |
| Dagsboro | 19 | Sussex County | 1,016 |
| Frankford | 20 | Sussex County | 930 |
| Ellendale | 21 | Sussex County | 571 |
| South Bethany | 22 | Sussex County | 535 |
| Dewey Beach | 23 | Sussex County | 416 |
| Fenwick Island | 24 | Sussex County | 400 |
| Bethel | 25 | Sussex County | 274 |
| Henlopen Acres | 26 | Sussex County | 162 |
| Galestown | 27 | Sussex County | 115 |
Sussex County is the county generally considered as South Delaware.