Allen
- County:
- Collin County
- County Seat:
- No
- Area (mi²):
- 26.385
- State:
- Texas
Allen is a city located in Collin County, Texas. Allen has a 2026 population of 113,746. Allen is currently growing at a rate of 0.79% annually and its population has increased by 7.76% since the most recent census, which recorded a population of 105,556 in 2020.