St. John the Baptist Diocesan High School is a private Catholic high school that serves students in grades nine through 12. The school offers a variety of advanced placement courses that are taught at the college level and conclude with advanced placement tests prepared by Educational Testing Services. It runs various departments that include arts, English, math, science and social studies. The school also operates a world languages department that conducts classes in French, Spanish and Latin. St. John the Baptist Diocesan High School is fully accredited by the Board of Regents of the University of the State of New York and by the Middle States Association of Colleges and Secondary Schools. The school is located in West Islip, N.Y.