Adjacent to the main body of the Chapel is the Oratory. Priest-faculty could celebrate daily Mass in one of the Oratory's three recessed chaples before concelebration became widespread practice.
Altar of Our Lady of Guadalupe
Our Lady of Guadalupe is accompanied on the right by St. Juan Diego to who she appeared in 1531. On the left is the Franciscan Bishop Juan de Zumarraga who is holding a replica of the Mexican Shrine of Our Lady of Guadalupe in his left hand.
Altar of the Sacred Heart of Jesus
The beautiful painting of the Sacred Heart of Jesus is surrounded by Pope Leo XIII, and Saints connected with te propagation of the devotion to the Sacred Heart of Jesus. People from every rank of life can be seen in the distance.
Altar of Saint Joseph
Our Blessed Lord is depicted anointing St. Joseph shortly before the latter's death. At the foot of the bed is our Blessed Mother. The contrast of the brilliant of and angel to the light of the candle as well as the household implements at the side are examples of Serbaroli's great genus for juxtaposition.
Opposite to the altars are three beautifully ornamented stained glass windows produced by three different glass studios in Dublin, Ireland. They were acquired by Archbishop Cantwell at the 1938 World's Fair in New York.
The window designed by Clarke Studios, depicts the homage of Saint Patrick to our Lady and the Infant Jesus.
The Annunciation is the subject of the center window which was created by William Earley Studios.
Harcourt Craft Studios designed the other window which depicts the Trinity of the Irish saints, Patrick, Brigid and Columbkille.
From the Oratory's south doorway is the entrance to the Sacristy, which houses amon other things, long rows of vestment cases and the chalice of Pope Pius XII. The precious chalice was a gift to Archbishop Cantwell in commemoration of the centennial of the Catholic Church in California. The chalice was presented to the Archbishop by the Most Rev. Amleto G. Cicognani, Apostolic Delegate to the Church of the United States.