Walter G. O'Connell Copiague High School is an American four-year college preparatory public high school in the hamlet of Copiague in Suffolk County, New York. Commonly referred to as "Copiague High School," the school is named after its founder and first principal Walter G. O'Connell. Walter G. O'Connell Copiague High School serves approximately 1,545 students in grades nine through twelve.