The Allen Independent School District has 17 elementary schools, 3 middle schools, 1 freshman center, 1 Alternative Education 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 High School’s football team has won the 5A Div 1 state championship on multiple occasions. They defeated Fort Bend Hightower 21–14, winning the 2008 Championship. Allen High School became State Champions again in 2012 winning 35-21 against Lamar High School at Cowboys Stadium in Arlington. They repeated as state champions in 2013, defeating Pearland High School by a score of 63-28 and capping their first 16-0 record in school history. Eagle Stadium opened on August 31, 2012 at a cost of $60 million.

The Allen Eagle Escadrille, Allen High School’s marching band with more than 750 members, 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 and 2016. The Allen Escadrille was a recipient of the Sudler Shield Award by the John Phillip Sousa Foundation in 2004.