Montini Catholic High School (often shortened to Montini) is a co-educational, college preparatory, high school, run by the Christian Brothers in Lombard, Illinois. It is located in the Roman Catholic Diocese of Joliet in Illinois. The school was planned by the Christian Brothers in 1963. Pope Paul VI, whose name was Giovanni Battista Montini (John Baptist Montini), was elected to the Papacy that same year. In his honor, the Christian Brothers named the school Montini Catholic High School. Construction of the buildings took place in 1965 and 1966. In September 1966, Montini Catholic High school opened its doors to 217 freshmen. The first commencement exercises were held on June 1, 1970.