Allen is a city in Collin County in the U.S. state of Texas, and a northern suburb in the Dallas–Fort Worth metroplex. The population was 104,627 at the 2020 census, and was estimated to be 111,551 in 2022. Allen is located approximately twenty miles (32 km) north of downtown Dallas and is a part of the Dallas–Fort Worth metropolitan area.

Collin County is located in the U.S. state of Texas. It is part of the Dallas-Fort Worth-Arlington metropolitan statistical area, and a small portion of the city of Dallas is in the county. At the 2020 United States census, the county's population is 1,064,465, making it the sixth-most populous county in Texas and the 43rd-largest county by population in the United States. Its county seat is McKinney.