Established in 1959, it is part of the Fullerton Joint Union High School District.

The campus, consisting mostly of single-story open plan buildings, is situated on 42 acres (170,000 m2) in western Fullerton.

[4] SHHS has been an International Baccalaureate World School since 1987, and hosts the largest IB program in California.

It has been recognized four times as a California Distinguished School, in 1988, 1994, 2009, and 2019, and recognized as one of the top high schools in the United States in the March 30, 1998, March 13, 2000, and June 2003 issues of Newsweek magazine.

[6] Sunny Hills was presented with the National Blue Ribbon School Award in 2012.