The school was founded in September 1961 by the Reverend Monsignor Robert T. Bulman and is located on a small portion of the parish's 32-acre (130,000 m2) campus.

Mater Dei was a part of St. Mary Parish and later operated under the supervision of the Roman Catholic Diocese of Trenton.

[13] A few days after the announcement, it was disclosed that the Parish Finance Council had agreed to a two-month extension in order to raise the $1 million needed to remain open.

[28] The boys soccer team won the Non-Public Group B state championship in 1981 and 1983, against runner-up Eastern Christian High School both years in the finals of the tournament.

[29] The 1983 team finished the season with a 16-4 record after defeating Eastern Christian by a score of 3-1 at Mercer County Park in the Parochial B finals.

[30] The boys tennis team won the Non-Public B/C state championship in 1981, defeating Oratory Preparatory School in the final match of the tournament.

[33] The girls tennis team won the Non-Public B state championship in 1982, defeating Pope John XXIII Regional High School 5-0 in the tournament final.

[36] The softball team won the Group II state championship in 2008, defeating Montclair Kimberley Academy in the finals of the tournament.