About St. John’s Prep. St. John’s Prep is an inclusive, Catholic, Xaverian Brothers Sponsored School for young men in grades 6 through 12. Founded on the Xaverian values of compassion, humility, simplicity, trust, and zeal, we educate students to be, do and stand for good in the world. We enroll approximately 1,500 students from more than 90 communities in Massachusetts, New Hampshire, and Maine. St. John’s is a faith-based community grounded in ...