28 cities
| City | Rank | 2025 Pop. ↓ | 2020 Pop. | Annual Change | Density | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plano | 1 | 295,002 | 286,422 | 0.59% | 4,114 | 72 | City |
| Frisco | 2 | 243,319 | 202,764 | 3.45% | 3,548 | 69 | City |
| McKinney | 3 | 235,030 | 197,510 | 3.3% | 3,510 | 67 | City |
| Allen | 4 | 115,793 | 105,556 | 1.8% | 4,386 | 26 | City |
| Wylie | 5 | 64,221 | 57,883 | 2.01% | 2,907 | 22 | City |
| Celina | 6 | 60,122 | 17,816 | 16.38% | 1,260 | 48 | City |
| Prosper | 7 | 47,924 | 30,818 | 7.69% | 1,902 | 25 | Town |
| Princeton | 8 | 41,881 | 17,569 | 13.13% | 4,147 | 10 | City |
| Anna | 9 | 35,594 | 17,552 | 11.28% | 1,997 | 18 | City |
| Melissa | 10 | 29,158 | 14,336 | 11.32% | 2,546 | 11 | City |
| Murphy | 11 | 21,115 | 21,082 | 0.03% | 3,706 | 6 | City |
| Fairview | 12 | 11,045 | 10,427 | 1.13% | 1,245 | 9 | Town |
| Josephine | 13 | 10,443 | 2,260 | 18.58% | 5,779 | 2 | City |
| Lavon | 14 | 9,477 | 4,544 | 11.61% | 2,810 | 3 | City |
| Lucas | 15 | 9,132 | 7,670 | 3.3% | 585 | 16 | City |
| Parker | 16 | 6,533 | 5,527 | 3.17% | 768 | 9 | City |
| Farmersville | 17 | 4,533 | 3,625 | 4.16% | 1,104 | 4 | City |
| Lowry Crossing | 18 | 2,112 | 1,689 | 4.14% | 815 | 3 | City |
| Nevada | 19 | 1,557 | 1,324 | 3.04% | 653 | 2 | City |
| Seis Lagos | 20 | 1,555 | 899 | 7.17% | 2,051 | 1 | CDP |
| Westminster | 21 | 1,431 | 768 | 2.73% | 359 | 4 | CDP |
| Blue Ridge | 22 | 1,264 | 1,181 | 1.28% | 1,075 | 1 | City |
| Weston | 23 | 1,092 | 282 | 17.42% | 243 | 4 | City |
| St. Paul | 24 | 1,004 | 991 | 0.2% | 700 | 1 | Town |
| New Hope | 25 | 688 | 665 | 0.58% | 480 | 1 | Town |
| Union Valley | 26 | 544 | 378 | 6.46% | 221 | 2 | City |
| Hebron | 27 | 218 | 221 | -0.46% | 813 | 0 | Town |
| Mobile City | 28 | 176 | 140 | 4.14% | 11,733 | 0 | City |
Plano is the largest city in Collin County, with a population of 295,002.
Mobile City is the smallest city in Collin County, with a population of 176.
There are 28 cities in Collin County, Texas.