28 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plano | 1 | 292,711 | 286,408 | 0.43% | 4,082 | 72 | City |
| Frisco | 2 | 239,842 | 202,754 | 3.19% | 3,497 | 69 | City |
| McKinney | 3 | 224,183 | 197,497 | 2.44% | 3,348 | 67 | City |
| Allen | 4 | 115,668 | 105,548 | 1.78% | 4,381 | 26 | City |
| Wylie | 5 | 63,210 | 57,879 | 1.72% | 2,861 | 22 | City |
| Celina | 6 | 60,323 | 17,808 | 16.41% | 1,264 | 48 | City |
| Prosper | 7 | 48,889 | 30,816 | 7.98% | 1,940 | 25 | Town |
| Princeton | 8 | 35,020 | 17,537 | 11.09% | 3,468 | 10 | City |
| Anna | 9 | 34,255 | 17,370 | 10.94% | 1,922 | 18 | City |
| Melissa | 10 | 29,727 | 14,336 | 11.55% | 2,596 | 11 | City |
| Murphy | 11 | 20,812 | 21,082 | -0.26% | 3,653 | 6 | City |
| Fairview | 12 | 11,032 | 10,426 | 1.11% | 1,244 | 9 | Town |
| Josephine | 13 | 10,351 | 2,255 | 18.54% | 5,728 | 2 | City |
| Lavon | 14 | 9,468 | 4,535 | 11.64% | 2,807 | 3 | City |
| Lucas | 15 | 9,288 | 7,673 | 3.6% | 595 | 16 | City |
| Parker | 16 | 6,636 | 5,526 | 3.46% | 780 | 9 | City |
| Farmersville | 17 | 4,541 | 3,625 | 4.2% | 1,106 | 4 | City |
| Lowry Crossing | 18 | 1,673 | 1,690 | -0.18% | 645 | 3 | City |
| Seis Lagos | 19 | 1,555 | 899 | 7.17% | 2,051 | 1 | CDP |
| Nevada | 20 | 1,482 | 1,324 | 2.21% | 621 | 2 | City |
| Westminster | 21 | 1,431 | 768 | 2.73% | 359 | 4 | CDP |
| Blue Ridge | 22 | 1,212 | 1,181 | 0.5% | 1,031 | 1 | City |
| Weston | 23 | 1,168 | 287 | 17.74% | 260 | 4 | City |
| St. Paul | 24 | 982 | 991 | -0.2% | 685 | 1 | Town |
| New Hope | 25 | 681 | 666 | 0.44% | 475 | 1 | Town |
| Union Valley | 26 | 559 | 379 | 6.88% | 227 | 2 | City |
| Hebron | 27 | 222 | 226 | -0.45% | 828 | 0 | Town |
| Mobile City | 28 | 173 | 142 | 3.59% | 11,533 | 0 | City |
Plano is the largest city in Collin County, with a population of 292,711.
Mobile City is the smallest city in Collin County, with a population of 173.
There are 28 cities in Collin County, Texas.