| City | Rank | 2026 Pop. ↓ | 2020 Pop. | Annual Change | Density (/mi²) | Area (mi²) | Type |
|---|---|---|---|---|---|---|---|
| Plano | 1 | 294,773 | 286,414 | 0.6% | 4,111 | 72 | City |
| Frisco | 2 | 245,057 | 202,749 | 3.42% | 3,573 | 69 | City |
| McKinney | 3 | 243,498 | 197,507 | 3.18% | 3,545 | 69 | City |
| Allen | 4 | 115,492 | 105,555 | 1.8% | 4,377 | 26 | City |
| Celina | 5 | 72,848 | 18,033 | 13.07% | 1,485 | 49 | City |
| Wylie | 6 | 65,094 | 57,897 | 1.96% | 3,076 | 21 | City |
| Prosper | 7 | 49,025 | 30,829 | 7.5% | 1,943 | 25 | Town |
| Princeton | 8 | 48,362 | 17,501 | 11.12% | 3,354 | 14 | City |
| Anna | 9 | 38,840 | 17,616 | 10.2% | 2,179 | 18 | City |
| Melissa | 10 | 32,928 | 14,339 | 9.87% | 2,875 | 11 | City |
| Murphy | 11 | 20,991 | 21,083 | 0.03% | 3,685 | 6 | City |
| Lavon | 12 | 12,869 | 4,541 | 8.25% | 2,998 | 4 | City |
| Josephine | 13 | 11,843 | 2,283 | 16.02% | 5,550 | 2 | City |
| Fairview | 14 | 11,037 | 10,425 | 1.14% | 1,244 | 9 | Town |
| Lucas | 15 | 9,193 | 7,674 | 3.34% | 589 | 16 | City |
| Parker | 16 | 6,665 | 5,527 | 3.14% | 784 | 9 | City |
| Farmersville | 17 | 5,716 | 3,728 | 3.34% | 1,392 | 4 | City |
| Lowry Crossing | 18 | 2,603 | 1,690 | 3.25% | 1,004 | 3 | City |
| Nevada | 19 | 1,570 | 1,321 | 3.15% | 658 | 2 | City |
| Weston | 20 | 1,303 | 284 | 14.3% | 290 | 4 | City |
| Blue Ridge | 21 | 1,283 | 1,181 | 1.42% | 1,091 | 1 | City |
| St. Paul | 22 | 996 | 985 | 0.2% | 695 | 1 | Town |
| New Hope | 23 | 692 | 667 | 0.73% | 483 | 1 | Town |
| Union Valley | 24 | 579 | 380 | 6.43% | 218 | 3 | City |
| Hebron | 25 | 181 | 184 | -0.55% | 675 | 0 | Town |
| Mobile City | 26 | 178 | 143 | 3.49% | 11,867 | 0 | City |
Plano is the largest city in Collin County, with a population of 294,773.
Mobile City is the smallest city in Collin County, with a population of 178.
There are 26 cities in Collin County, Texas.