High Quality Content by WIKIPEDIA articles! Sacred Heart High School is a private, Roman Catholic high school in Waterbury, Connecticut. It is located in the Roman Catholic Archdiocese of Hartford.Sacred Heart was established in 1922 as an all-girls school. The school became coeducational in 1938. Since 1975, the school has been located in the old Waterbury Catholic High School building in downtown Waterbury. High school is the name used in some parts of the world, particularly in Scotland, Northern America, and Oceania to describe an institution that provides all or part of secondary education.