Semiahmoo Secondary School ( SEM-ee-AM-moo) is a public high school in South Surrey, British Columbia, and is part of School District 36 Surrey. It was founded in 1940 as the first senior secondary school in South Surrey. The school serves grades eight through twelve.

Semiahmoo is one of four public high schools on the peninsula, along with Earl Marriott Secondary School, Elgin Park Secondary School and Grandview Heights Secondary School.

The school is named after the Indigenous Semiahmoo people.