Allen is a city in Collin County, Texas, United States, a northern suburb of Dallas. As of the 2010 United States Census, the city had a total population of 84,246. In 2019, the population of Allen is estimated to be 105,623. Allen is located approximately twenty miles (32.2 km) north of downtown Dallas and is a part of the Dallas-Fort Worth metropolitan area.
The Allen area was previously home to the Caddo, Comanche, and other indigenous peoples. The first immigrants from the United States and Europe arrived in the early 1840s. The town was established by the Houston and Central Texas Railroad and named in 1872 for Ebenezer Allen, a state politician and railroad promoter. The railroad allowed sale of crops across the country before they rotted, causing a shift from the previous cattle-based agriculture. On February 22, 1878, a gang led by Sam Bass committed in Allen what is said to be Texas's first train robbery.
From 1908 through 1948, Allen was a stop along the Texas Traction Company's interurban line from Denison to Dallas. Allen was a small town of a few hundred residents when it was incorporated in 1953.