Eastside High School (Lancaster, California)

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. Before 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. A school's Academic Performance Index (API) is a scale that ranges from 200 to 1000 and is calculated from the school's performance in the California Assessment of Student Performance and Progress (CAASPP) Program. The state has set 800 as the API target for all schools to meet.

Eastside High School had an API growth score of 660 in 2010 and currently has maintained their API growth of 660. California uses the Academic Performance Index (API) to measure annual school performance and year-to-year improvement. Eastside High School's 2010 base score was 630 and the school did meet its 2010 school-wide growth target.

Eastside High School has numerous extra curricular activities for their students such as: a dual gender band, a dual gender wrestling team, separate gender basketball teams, separate gender volleyball teams, an isolated sex baseball team, an isolated sex softball team, a dual gender football team and girls flag football.

The school mascot is the Eastside Lion with school colors of purple and black.