Delone Catholic High School is a regional high school named for Charles J. Delone, Esquire, a prominent Catholic attorney of Hanover, who donated the land and the funds for the construction of the original building. The facilities that had been the education center for elementary and high school had been destroyed by fire in 1938 which precipitated Mr. Delone's generous donation. The cornerstone of the new school was laid in 1939 and the new building was dedicated by Archbishop Amleto Giovanni Cicognani, Apostolic Delegate to the United States, on September 2, 1940. As a tribute to Mr. Delone, the school bears his name and its athletic teams have adopted his title "Squires" and "Squirettes."
Father Cyril J. Allwein was appointed the first principal of Delone Catholic High School. The Sisters of Saint Joseph were joined on the faculty by the Sisters of Mercy and, in 1941, by the Sisters of Christian Charity.
In 1952, the high school was accredited by the Middle States Association under the direction of Father William R. Lyons, Principal 1948-1977. Two additional wings were added to the original building in 1955 and in 1962. A chapel, bearing the title, "Our Lady, Queen of Peace," was constructed in 1966. The Lawrence B.(Sonny) Sheppard Memorial, a gymnasium complex, the gift of Mr. and Mrs. L. B. Sheppard in memory of their son, was built in 1968. the 1963 Math and Science Wing underwent significant renovations, including the addition of new heating and air conditioning units and educational technology, as well as floor, ceiling and bathroom upgrades. An additional science laboratory was added.