The Theresianum Gymnasium is an all-day high school located in Mainz, Germany. It was founded in 1927 by the Johannesbund e.V..The high school is a Catholic school and still sponsored by the Roman Catholic Diocese of Mainz. This does not mean that the school does not accept students with a different religion. Students have the opportunity to achieve the highest academic high school degree, the Abitur after 12th grade while they enroll in school for 5th grade.