1906-1908 Fr. Michael Kozlowski
1908-1941 Fr. John Czaplinski
1941-1942 Fr. Ted Wisniewski
1942-1980 Fr. John Styka
1980-1996 Fr. Ernest Strzelinski
1996-2007 Fr. Andrew Fischer
2007-2009 Fr. Frank D. Almade
St. John Cantius was established in 1906 as a Polish nationality parish. The origin of the parish can be traced to the immigration of Poles to Sharpsburg in the late nineteenth century. At first local Poles traveled to Pittsburgh to attend Mass at St. Stanislaus Kostka Parish in the Strip District. When Holy Family Parish was founded in 1902 in Lawrenceville, Sharpsburg Poles attended that church. However, they wanted their own congregation and on October 14, 1906, the parish was established by the appointment of a resident pastor.
The new parish made arrangements with Madonna of Jerusalem parish to use their church until St. John Church was built. Work on a combined church and school began in June of 1907. The basement and the first floor were intended to hold the school and the second floor the church. The cornerstone was laid on August 18, 1907, and the completed building was dedicated on January 26, 1908.
On June 15, 1965, a fire broke out in the building which completely destroyed the church and badly damaged the school. The parish razed the second floor church and repaired the school in the lower floors. During this time, the parish celebrated Mass in the parish recreational hall. The school reopened in March of 1966. However, it took five years before work began on the new church. Construction began in April of 1970 and the first Mass in the new church was celebrated on Christmas Day, 1970. The church was dedicated on February 28, 1971.
In 2008 the Korean Catholic Community, which had been established in 1989 and had been sharing the facilities of St. Pamphillus Parish, Beachview, came to St. John Cantius. Their chaplain moved into the rectory, and KCC parishioners used the rectory and downstairs social hall for religious education classes and social events.