There are several works of art in the Cathedral. Of special note is the magnificent bas-relief at the rear of the main church. It is hand-carved marble and depicts the life of Christ. This dates to the 1921 restoration and was the frontispiece of the main altar which was dismantled in the 1967 renovations. During the Millennium Restoration of the Cathedral, the bas-relief was found in three pieces in the basement of the Chapel and restored to its original beauty.

There are three beautiful contemporary paintings by Michael Waterman, a noted American artist, Portland resident and graduate of Cathedral School. Many of his paintings reflect religious themes.

The moving portrait of the Crucifixion hangs on the wall to the right of the Sanctuary. Its dark and somber colors remind us of Luke's Gospel: "It was now about the sixth hour and, with the sun eclipsed, a darkness came over the whole land until the ninth hour" (Luke 23:44).

The second Waterman painting shows Christ at the table with his Apostles. It is the artist's interpretation of the Miracle of the Loaves and Fishes: "Then he took the five loaves and the two fish, raised his eyes to heaven, and said the blessing over them; then he broke them and handed them to his disciples to distribute among the crowd. They all ate as much as they wanted, and when the scraps remaining were collected they filled 12 baskets" (Luke 9:16-17).

Michael Waterman's third painting depicts St. John the Baptist baptizing. In his left hand he is holding a lamb, the symbol of Christ, which represents the New Testament. The lamb is standing on a book, which represents the Old Testament.

These last two Waterman paintings hang in the rear vestibule of the Cathedral.

Another lovely painting to the left of the stairs leading to the Chapel is the Madonna of Barabino in a magnificent gold Gothic frame. The legend below the Madonna says "Mater Amabilis." Bishop Louis Walsh purchased this painting in 1923 for the "Special price" of $500. It was part of the 1921 restoration.

To the left of Mary's altar is the painting of Bishop David W. Bacon (1855-1874), the Cathedral's first Bishop. Next to it is a handsome bronze plaque memorializing his life. He had taken as his motto, "Courage and Hope" (Robur ac Spes). The plaque is in Latin.

The newest acquisition is "The Baptism of Christ" by Dimitar Todorov Malchev, a noted Bulgarian artist. This painting hangs on the wall behind the exquisite Baptismal Font. He painted this in 19th century style. The rays emit from the Holy Spirit onto Christ while St. John baptized him in the presence of three hovering angels. The ornate crucifix (labarum) at the top of the frame is a symbol, which appeared to the Emperor Constantine the Great prior to battle. The symbols "X" and "P" represent the name of Christ. The Alpha and Omega symbols represent the eternity of Christ, "I am the beginning and the end, I am that am."

In the Sacristy are busts of Bishop Louis S. Walsh, our Fourth Bishop (1906-1924), who is buried in our Cathedral Crypt, along with Bishop David W. Bacon (1855-1874), our first Bishop. Archbishop John J. Williams of Boston is also represented, as is a Carrara marble bust of Pope St. Pius X which he presented to our Diocese during his papal reign (1903-1914).
 
In the Upper Sacristy meeting room are many old paintings of our Bishops (one lovely one in color of Bishop Louis Walsh), as well as several photographs dating to the early years of the Cathedral and Cathedral School.