Father MacKavanagh Memorial Hall first opened in 1967 in order to house Prep's science and language facilities. Named for Rev. Kelvin T. MacKavanagh, S.J., a Jesuit priest and teacher fondly known by students as "Father Mac," MacKavanagh Hall allowed for the expansion of Prep's growing student body.
MacKavanagh Hall is a three-story classroom building that contains twelve classrooms, three science labs, a language lab, lecture hall, and administrative offices.