61 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Upper Darby | 1 | 86,622 | 85,590 | 0.67% | 11,070 | 8 | Township |
| Chester | 2 | 34,391 | 32,695 | 1% | 7,116 | 5 | City |
| Radnor | 3 | 34,355 | 33,214 | 0.66% | 2,495 | 14 | Township |
| Ridley | 4 | 31,353 | 30,943 | 0.69% | 6,130 | 5 | Township |
| Springfield | 5 | 25,378 | 25,050 | 0.68% | 4,015 | 6 | Township |
| Marple | 6 | 24,606 | 24,202 | 0.75% | 2,412 | 10 | Township |
| Springfield | 7 | 21,284 | 20,807 | 0.53% | 3,163 | 7 | Township |
| Upper Chichester | 8 | 17,118 | 16,880 | 0.68% | 2,560 | 7 | Township |
| Aston | 9 | 16,944 | 16,792 | 0.63% | 2,901 | 6 | Township |
| Nether Providence | 10 | 14,663 | 14,400 | 0.71% | 3,111 | 5 | Township |
| Yeadon | 11 | 12,497 | 12,034 | 0.74% | 7,835 | 2 | Borough |
| Lansdowne | 12 | 11,260 | 11,084 | 0.31% | 9,534 | 1 | Borough |
| Upper Providence | 13 | 11,010 | 10,865 | 0.67% | 1,966 | 6 | Township |
| Darby | 14 | 10,761 | 10,699 | 0.11% | 12,780 | 1 | Borough |
| Darby | 15 | 9,324 | 9,210 | 0.68% | 6,585 | 1 | Township |
| Collingdale | 16 | 8,971 | 8,893 | 0.17% | 10,323 | 1 | Borough |
| Brookhaven | 17 | 8,435 | 8,295 | 0.33% | 4,939 | 2 | Borough |
| Ridley Park | 18 | 7,322 | 7,261 | 0.16% | 6,786 | 1 | Borough |
| Glenolden | 19 | 7,276 | 7,224 | 0.14% | 7,463 | 1 | Borough |
| Thornbury | 20 | 7,036 | 6,893 | 0.61% | 762 | 9 | Township |
| Clifton Heights | 21 | 6,889 | 6,843 | 0.13% | 10,935 | 1 | Borough |
| Folcroft | 22 | 6,835 | 6,792 | 0.12% | 5,490 | 1 | Borough |
| Swarthmore | 23 | 6,613 | 6,528 | 0.26% | 4,724 | 1 | Borough |
| Prospect Park | 24 | 6,460 | 6,419 | 0.12% | 8,825 | 1 | Borough |
| Springfield | 25 | 6,191 | 6,029 | 0.75% | 235 | 26 | Township |
| Sharon Hill | 26 | 6,046 | 6,009 | 0.12% | 7,832 | 1 | Borough |
| Norwood | 27 | 5,977 | 5,936 | 0.13% | 7,683 | 1 | Borough |
| Media | 28 | 5,952 | 5,880 | 0.24% | 7,801 | 1 | Borough |
| Wayne | 29 | 5,417 | 5,206 | 1.06% | 154 | 35 | Township |
| Springfield | 30 | 5,279 | 5,169 | 0.84% | 173 | 31 | Township |
| Edgmont | 31 | 4,792 | 4,292 | 1.7% | 494 | 10 | Township |
| Aldan | 32 | 4,282 | 4,254 | 0.12% | 7,173 | 1 | Borough |
| Chester | 33 | 4,104 | 4,066 | 0.59% | 2,874 | 1 | Township |
| Tinicum | 34 | 4,038 | 3,980 | 0.67% | 702 | 6 | Township |
| Chadds Ford | 35 | 4,034 | 3,968 | 0.82% | 466 | 9 | Township |
| Lower Chichester | 36 | 3,441 | 3,403 | 0.64% | 3,207 | 1 | Township |
| Chester Heights | 37 | 3,129 | 2,918 | 1.36% | 1,413 | 2 | Borough |
| Upland | 38 | 3,080 | 3,059 | 0.13% | 4,746 | 1 | Borough |
| Springfield | 39 | 3,012 | 3,075 | -0.23% | 81 | 37 | Township |
| Morton | 40 | 2,793 | 2,768 | 0.18% | 7,802 | 0 | Borough |
| East Lansdowne | 41 | 2,727 | 2,710 | 0.11% | 13,238 | 0 | Borough |
| Springfield | 42 | 2,606 | 2,727 | -0.8% | 44 | 59 | Township |
| Colwyn | 43 | 2,486 | 2,471 | 0.12% | 9,636 | 0 | Borough |
| Marcus Hook | 44 | 2,470 | 2,455 | 0.12% | 2,229 | 1 | Borough |
| Eddystone | 45 | 2,467 | 2,455 | 0.08% | 2,479 | 1 | Borough |
| Wayne | 46 | 2,400 | 2,466 | -0.54% | 149 | 16 | Township |
| Wayne | 47 | 2,350 | 2,360 | -0.04% | 48 | 49 | Township |
| Parkside | 48 | 2,337 | 2,324 | 0.09% | 11,345 | 0 | Borough |
| Trainer | 49 | 1,985 | 1,978 | 0.05% | 1,878 | 1 | Borough |
| Springfield | 50 | 1,826 | 1,854 | -0.16% | 67 | 27 | Township |
| Wayne | 51 | 1,501 | 1,537 | -0.33% | 39 | 38 | Township |
| Wayne | 52 | 1,453 | 1,453 | 0.07% | 65 | 22 | Township |
| Wayne | 53 | 1,402 | 1,407 | -0.07% | 40 | 35 | Township |
| Wayne | 54 | 1,297 | 1,266 | 0.62% | 93 | 14 | Township |
| Wayne | 55 | 1,246 | 1,295 | -0.95% | 28 | 45 | Township |
| Millbourne | 56 | 1,218 | 1,211 | 0.08% | 16,459 | 0 | Borough |
| Springfield | 57 | 1,127 | 1,147 | -0.27% | 27 | 41 | Township |
| Rose Valley | 58 | 1,021 | 1,015 | 0.1% | 1,395 | 1 | Borough |
| Wayne | 59 | 994 | 1,025 | -1% | 25 | 39 | Township |
| Rutledge | 60 | 788 | 785 | 0% | 5,510 | 0 | Borough |
| Springfield | 61 | 679 | 693 | -0.29% | 25 | 28 | Township |
Upper Darby is the largest city in Delaware County, with a population of 86,622.
Springfield is the smallest city in Delaware County, with a population of 679.
There are 61 cities in Delaware County, Pennsylvania.