The history of Saint Francis de Sales Catholic Church can be traced back to the early 1800's. The first Mass was celebrated in Patchogue in 1850 by Father Castella, a traveling priest from Smithtown. The Catholic community of Patchogue held Mass in homes until 1854 when they united to purchase the former Methodist church that wasidentified as 'The Mission Church'. It was a. bungalow-type structure with a large potbelly stove and could accommodate about forty people.
Over time, the original church became too small for the growing community of St. Francis de Sales. A parcel of land on the comer of East Main Street and Conklin Avenue was purchased by Rev. Felix O'Callahan, the first pastor of St. Francis de Sales Parish. It was here that our present church was built. Stanford White, a renowned architect, designed the church. He also designed the Library of Congress, Madison Square Garden and the His Excellency John Loughlin, Bishop of Brooklyn. In 1906, it was felt that the church should be moved into the center of Patchogue. Father James; J. Cronin moved the building to its present location. The moving of the church created quite a stir and men had to stand 'guard duty' at night to prevent problems due to anti-Catholic sentimen at the time.
Besides moving the church, Father Cronin guided the people of St. Francis de Sales through difficult times. In 1914, the Ku Klux Klan had caused enough difficulties to the Catholic community that Fr. Cronin decided to respond by organizing a 'Holy Name Parade' to march through Patchogue. Over 25,000 Catholics from the surrounding areas came to march in the parade to show solidarity of the church.
In 1922, Father Cronin built the first Catholic school in the area. It was staffed by the Sisters of the Holy Union of the Sacred Hearts of Jesus and Mary.. In 1950, the Edwin Bailey house and property were purchased and became the new convent. It remained as a convent until the early 1990's when it was changed to the Parish Center. A new school was built on the land behind the convent in 1960. Today it is known as "Holy Angels Regional School" and serves seven Catholic parishes.
Under the direction of co-pastors Father Thomas Haggerty and Father Frederick Schaefer, the church was renovated in 1995. Later, Father Robert Clerkin made needed repairs to the church foundation and throughout all the parking lots. In 2003, under the direction of Father Kevin Smith, the parish purchased the old private home between the church and the Parish Center. That house was torn down and the parish property has been enhanced to its present state.