Mater Dei High School opened in 1949 on the west side of Evansville, Indiana as a Catholic, diocesan, coeducational high school to serve the needs of a growing community. Bishop Henry J, Grimmelsman named the school in honor of Mary, Mother of God, who serves as the school's patroness. The school is one of two Catholic high schools in Evansville and serves the students of Vanderburgh, Posey, Gibson, and Warrick counties.