Allen is a city in Collin County, Texas, United States, a northern suburb of Dallas. As of the 2010 census the city had a total population of 84,246. According to the City of Allen, the city has a total area of 27.1 square miles (70 km2). None of the area is covered with water except the small ponds scattered throughout the city.
The Allen Independent School District has 17 elementary schools, 3 middle schools, 1 freshman Center, 1 Pat Dillard Special Achievement Center, and 1 high school (Allen High School). Allen ISD serves almost all of Allen. Small portions of the Allen city limits extend into Lovejoy, McKinney, and Plano ISDs. In the fall of 2006, new 9th grade high school students in the Lovejoy ISD boundaries began attending the newly opened Lovejoy High School. The school became a full 4-year high school in the 2009-10 school year. Allen hosts a campus of Collin College, which is located inside Allen High School.
Allen High School's football team won the 5A Div 1 state championship on December 20, 2008. They defeated Fort Bend Hightower 21–14. The Allen Eagle Escadrille, Allen High School's marching band, participated in the 1994 St. Patrick's Day Parade in Dublin, Ireland, the 1995 and 1999 Texas Gubernatorial Parades, the 1997 Macy's Thanksgiving Day Parade in New York City, and marched in the 117th Tournament of Roses Parade in Pasadena, California on January 2, 2006. They were also a recipient of the Sudler Shield Award by the John Phillip Sousa Foundation in 2004.