Notre Dame Catholic High School was founded in 1955 by the Most Reverend Lawrence Shehan, who believed "The future of our country depends on our youth.

To provide them with sound religious and moral training is a major concern of all of us.

"[2] The school, built on Park Avenue in Bridgeport, Connecticut, was a co-institution staffed by the Sisters of Notre Dame de Namur, the Holy Cross Fathers, Diocesan clergy and several lay men and women.

In 1956, the first classes of Notre Dame were held at Our Lady of Assumption school in Fairfield while the building was being completed.

In 1964, the school and property of Notre Dame became Sacred Heart University.