Saint Joseph's Oratory of is a Roman Catholic basilica on the west slope of Mount Royal in Montreal, Quebec, Canada.

In 1904, Saint Andr? Bessette, CSC, began the construction of a small chapel on the side of the mountain near Notre Dame College. Soon the growing number of visitors made it too small. Even though it was enlarged, a larger church was needed and in 1917 one was completed - it is called the Crypt, and has a seating capacity of 1,000. In 1924, the construction of the basilica was inaugurated; it was finally completed in 1967.

The Oratory's dome is the third-largest of its kind in the world after the Basilica of Our Lady of Peace of Yamoussoukro in the Ivory Coast and Saint Peter's Basilica in Rome, and the church is the largest in Canada.

The basilica is dedicated to Saint Joseph, to whom Brother Andr? credited all his reported miracles. These were mostly related to some kind of healing power, and many pilgrims (handicapped, blind, ill, etc.) poured into his Basilica, including numerous Protestants. On display in the basilica is a wall covered with thousands of crutches from those who came to the basilica and were allegedly healed. Pope John Paul II deemed the miracles to be authentic and beatified Brother Andr? in 1982.

A reliquary in the church museum contains Brother Andr?'s heart, which he requested as a protection for the basilica. More than 2 million visitors and pilgrims visit the Oratory every year.

In 2005, the Oratory was added to the List of National Historic Sites of Canada on the occasion of its 100th anniversary.