Charter Oak High School is a four-year comprehensive secondary school in the Charter Oak Unified School District. It is located in the City of Covina, California, in the San Gabriel Valley east of Los Angeles. The school serves 9th, 10th, 11th and 12th graders from the communities of Covina, Glendora and San Dimas. Enrollment in 2016-17 was 1,566. Charter Oak High School, which opened in 1959, is accredited by the Western Association of Schools and Colleges. Charter Oak High School was named a California Distinguished School in 1996 and 2007 and a 2015 Gold Ribbon School.