Seaside High School is a secondary school located in Seaside, California. The school first opened in September of 1963 to Sophomores and Juniors (incoming Seniors continued to attend Monterey High School until graduation), graduating its first class in June of 1965. This year Seaside is celebrating its 50th Anniversary! Average annual enrollment is 1,200 students, attending grades 9–12. The school serves the communities of Seaside, Monterey, Marina, Sand City, and Del Rey Oaks. Its student body reflects the region's diversity of language, ethnicity, nationality, and cultures.