The John Carroll School (est. 1964) is an independent, college-preparatory, co-educational Catholic school for grades 9–12 in Bel Air, MD, in the Roman Catholic Archdiocese of Baltimore. The School is named after John Theodore Carroll, SJ, the first Catholic bishop and archbishop in the United States — serving as the ordinary of the Roman Catholic Archdiocese of Baltimore. In the early 1960s, the decision was made by Cardinal Lawrence Shehan to build an Archdiocesan Catholic high School on a 72-acre site in Harford County, Maryland. The John Carroll School opened to 202 freshmen on September 9, 1964, under the leadership of Principal Reverend Raymond Wanner. In 1971, The John Carroll School, in an agreement with the Archdiocese of Baltimore, became an independent Catholic School, operated by its own elected Board of Trustees and administrated by a principal. In 2008, the Board of Trustees voted to change the organizational structure of the School to the president-principal model, which continues to this day.