In 1873, Archbishop John Williams asked the Franciscans of the Immaculate Conception Province to minister to Boston's growing population of Italian immigrants.

Construction of the current building, designed in the Romanesque style by architect William Holmes,[2] did not begin until 1885.

[3] The interior, with its ornate Italian style and color scheme, was created by immigrant craftsmen who were also parishioners.

Antonio Sousa, the pastor of St. Leonard's Church at the time, founded the Home for Italian Children in Jamaica Plain to care for them.

St. Leonard's Church is known for its attractive Peace Garden, and for its St. Anthony shrine, which is the oldest of its kind in Boston.