61 cities
| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Upper Darby | 1 | 87,199 | 85,590 | 0.67% | 11,144 | 8 | Township |
| Chester | 2 | 34,730 | 32,695 | 0.99% | 7,186 | 5 | City |
| Radnor | 3 | 34,580 | 33,214 | 0.65% | 2,511 | 14 | Township |
| Ridley | 4 | 31,567 | 30,943 | 0.68% | 6,171 | 5 | Township |
| Springfield | 5 | 25,550 | 25,050 | 0.68% | 4,042 | 6 | Township |
| Marple | 6 | 24,789 | 24,202 | 0.74% | 2,430 | 10 | Township |
| Springfield | 7 | 21,397 | 20,807 | 0.53% | 3,180 | 7 | Township |
| Upper Chichester | 8 | 17,233 | 16,880 | 0.67% | 2,577 | 7 | Township |
| Aston | 9 | 17,050 | 16,792 | 0.63% | 2,919 | 6 | Township |
| Nether Providence | 10 | 14,767 | 14,400 | 0.71% | 3,133 | 5 | Township |
| Yeadon | 11 | 12,590 | 12,034 | 0.74% | 7,893 | 2 | Borough |
| Lansdowne | 12 | 11,295 | 11,084 | 0.31% | 9,564 | 1 | Borough |
| Upper Providence | 13 | 11,083 | 10,865 | 0.66% | 1,979 | 6 | Township |
| Darby | 14 | 10,774 | 10,699 | 0.12% | 12,796 | 1 | Borough |
| Darby | 15 | 9,387 | 9,210 | 0.68% | 6,629 | 1 | Township |
| Collingdale | 16 | 8,987 | 8,893 | 0.18% | 10,342 | 1 | Borough |
| Brookhaven | 17 | 8,463 | 8,295 | 0.33% | 4,955 | 2 | Borough |
| Ridley Park | 18 | 7,334 | 7,261 | 0.16% | 6,797 | 1 | Borough |
| Glenolden | 19 | 7,287 | 7,224 | 0.15% | 7,474 | 1 | Borough |
| Thornbury | 20 | 7,079 | 6,893 | 0.61% | 766 | 9 | Township |
| Clifton Heights | 21 | 6,898 | 6,843 | 0.13% | 10,949 | 1 | Borough |
| Folcroft | 22 | 6,844 | 6,792 | 0.13% | 5,497 | 1 | Borough |
| Swarthmore | 23 | 6,630 | 6,528 | 0.26% | 4,736 | 1 | Borough |
| Prospect Park | 24 | 6,468 | 6,419 | 0.12% | 8,836 | 1 | Borough |
| Springfield | 25 | 6,237 | 6,029 | 0.74% | 237 | 26 | Township |
| Sharon Hill | 26 | 6,054 | 6,009 | 0.13% | 7,842 | 1 | Borough |
| Norwood | 27 | 5,985 | 5,936 | 0.13% | 7,693 | 1 | Borough |
| Media | 28 | 5,967 | 5,880 | 0.25% | 7,820 | 1 | Borough |
| Wayne | 29 | 5,474 | 5,206 | 1.05% | 156 | 35 | Township |
| Springfield | 30 | 5,323 | 5,169 | 0.83% | 174 | 31 | Township |
| Edgmont | 31 | 4,872 | 4,292 | 1.67% | 502 | 10 | Township |
| Aldan | 32 | 4,288 | 4,254 | 0.14% | 7,183 | 1 | Borough |
| Chester | 33 | 4,128 | 4,066 | 0.58% | 2,891 | 1 | Township |
| Chadds Ford | 34 | 4,067 | 3,968 | 0.82% | 470 | 9 | Township |
| Tinicum | 35 | 4,065 | 3,980 | 0.67% | 707 | 6 | Township |
| Lower Chichester | 36 | 3,463 | 3,403 | 0.64% | 3,227 | 1 | Township |
| Chester Heights | 37 | 3,171 | 2,918 | 1.34% | 1,432 | 2 | Borough |
| Upland | 38 | 3,084 | 3,059 | 0.13% | 4,752 | 1 | Borough |
| Springfield | 39 | 3,005 | 3,075 | -0.23% | 80 | 37 | Township |
| Morton | 40 | 2,798 | 2,768 | 0.18% | 7,816 | 0 | Borough |
| East Lansdowne | 41 | 2,731 | 2,710 | 0.15% | 13,257 | 0 | Borough |
| Springfield | 42 | 2,585 | 2,727 | -0.81% | 44 | 59 | Township |
| Colwyn | 43 | 2,489 | 2,471 | 0.12% | 9,647 | 0 | Borough |
| Marcus Hook | 44 | 2,473 | 2,455 | 0.12% | 2,232 | 1 | Borough |
| Eddystone | 45 | 2,470 | 2,455 | 0.12% | 2,482 | 1 | Borough |
| Wayne | 46 | 2,387 | 2,466 | -0.54% | 148 | 16 | Township |
| Wayne | 47 | 2,349 | 2,360 | -0.04% | 48 | 49 | Township |
| Parkside | 48 | 2,340 | 2,324 | 0.13% | 11,359 | 0 | Borough |
| Trainer | 49 | 1,987 | 1,978 | 0.1% | 1,880 | 1 | Borough |
| Springfield | 50 | 1,823 | 1,854 | -0.16% | 67 | 27 | Township |
| Wayne | 51 | 1,496 | 1,537 | -0.33% | 39 | 38 | Township |
| Wayne | 52 | 1,454 | 1,453 | 0.07% | 65 | 22 | Township |
| Wayne | 53 | 1,401 | 1,407 | -0.07% | 40 | 35 | Township |
| Wayne | 54 | 1,305 | 1,266 | 0.62% | 94 | 14 | Township |
| Wayne | 55 | 1,234 | 1,295 | -0.96% | 28 | 45 | Township |
| Millbourne | 56 | 1,220 | 1,211 | 0.16% | 16,486 | 0 | Borough |
| Springfield | 57 | 1,124 | 1,147 | -0.27% | 27 | 41 | Township |
| Rose Valley | 58 | 1,022 | 1,015 | 0.1% | 1,396 | 1 | Borough |
| Wayne | 59 | 984 | 1,025 | -1.01% | 25 | 39 | Township |
| Rutledge | 60 | 789 | 785 | 0.13% | 5,517 | 0 | Borough |
| Springfield | 61 | 677 | 693 | -0.29% | 25 | 28 | Township |
Upper Darby is the largest city in Delaware County, with a population of 87,199.
Springfield is the smallest city in Delaware County, with a population of 677.
There are 61 cities in Delaware County, Pennsylvania.