The upper section is red, the symbol of the Holy Spirit, the divine protector of Catholic education. Two crowns, adorned with crosses pattee and fleur-de-lis, are taken from the arms of old Boston, England and the place of the third crown is filled with a gold mitre, representing the second Bishop of Boston, Bishop Benedict Joseph Fenwick. The cross Moline with the letters "N" and "D" cradled in each arm is from the seal of the Sisters of Notre Dame.
The trimount at the base represent the three hills upon which the City of Boston is built. The five silver and blue lines stand for the ever-present sea so much a part of New England. The trimount and the five lines are found upon the coat of arms of the Boston Archdiocese.
A silver edged scroll at the bottom of the escutcheon has inscribed on it in gold the school motto:
"BONITAS ET FIDELITAS"; "GOODNESS AND LOYALTY"
The official school colors are brown and gold.