Eastside High School is located in Lancaster, California and is part of the Antelope Valley Union High School District. Eastside is the 8th and newest school in the district. The school opened its doors to freshmen in August 2005, with the first class graduating in May 2009. Until May 2009, the school was housed in portables. Classes are now held at the newly constructed site adjacent to the former site.It is a public school that serves 2592 students in grades 9-12. The school mascot is the Eastside Lion with school colors of purple and black.