Mater Dei High School or Evansville Mater Dei High School is a private Catholic high school on the west side of Evansville, Indiana, constructed in 1949. It is one of two Catholic high schools that serve the students of Vanderburgh, Posey, Gibson, and Warrick counties as part of the Roman Catholic Diocese of Evansville. Extracurricular programs include: athletics, theater, music, speech, dance cats, and other clubs and organizations.