Saint Sebastian's School is an independent, all-boys Catholic secondary school located in Needham, Massachusetts on 26 acres (110,000 m²), in the Roman Catholic Archdiocese of Boston. The school instructs young men in grades seven through twelve. Founded in 1941 by William Cardinal O'Connell, Archbishop of Boston, the school is named after Saint Sebastian, the Christian martyr who survived an attempted execution by arrows. It is the only Catholic school in the Independent School League. Approximately 350 students are enrolled, with 25% receiving financial aid. Since 1990, the School headmaster is Mr. William L.