St. Patrick was founded in McHenry by Father Maurice de St. Palais in 1840 and was one of the pioneer parishes of northern Illinois and the third oldest parish in the Diocese of Rockford.

Despite St. Patrick's early formation, the neighboring town of Hartland had had a church for four years. It was to this church that McHenry area residents went for major church functions.

Masses that were offered before St. Patrick Church was built were said in homes, primarily those of James Wall, John and Michael Sutton, George Frisby and Mrs. Mary Behan.

The first St. Patrick Church was built in 1853 on land donated by James Gibbs. The building cost $700.00 and served the parish for almost 20 years.

Father P. M. O'Neill was the first long-term pastor of St. Patrick, serving from 1876 to 1906. He built an addition to the church in 1883. That church, which was the second parish, had been built by Father Peter Birch in 1872. Father O'Neill also had charge of the missions of Richmond, Wauconda and Fox Lake. Following Father O'Neill through 1915 were Father Paul Bourke, Father Daniel Lehane, Father Henry Hagen, Father Charles Quinn and Father Joseph Lynch.

Father Martin J. McEvoy became the pastor in July, 1915. In 1921, he began planning a new church. The cornerstone was laid in August, 1922, and the building was dedicated on St. Patrick's Day, March 17, 1923.

Father William O'Rourke succeeded Father McEvoy in February, 1926. Among his many achievements was a substantial reduction of the parish debt and redecorating the church. Father O'Rourke joined with Msgr. Nix in building the St. Patrick-St. Mary School in 1937. This school served the children of both parishes until St. Patrick Parish built its own parish school in 1951.

Father O'Rourke was seriously ill in his last years at St. Patrick. He was pastor until 1947 and pastor emeritus until his death in 1950. Father James Vanderpool was administrator for nine months during Father O'Rourke's illness.

Father O'Rourke was succeeded by Father Edward Coakley, who came in April of 1948. In 1951, under Father Coakley, a parochial school was built, making possible a separation from the school shared by St. Mary's. During that year, a convent was also secured. The school was staffed by the Sisters of Mercy.

Father Coakley was succeeded as pastor by Father Leonard Guzzardo in August of 1965. In 1965, the church was enlarged by opening the wall separating the winter chapel from the main church. The church hall and rectory were remodeled and the parking area was resurfaced.

In 1966, land was purchased for a new cemetery south of McHenry on Barreville road. In 1967, a new central heating system for the church, school and rectory was installed.

Father Guzzardo died in March, 1969 and was succeeded by Father Edmund P. Petit. In 1970, the two parochial schools were once again consolidated. With the consolidation, the St. Patrick's School building became the Montini Primary Center, grades 1-4, and the St Mary's building became the Montini Middle School, grades 5-8.

In, 1970, Father Petit redecorated the interior of the church to conform to the norms of Vatican Council II.

Father James V. McKitrick joined St. Patrick as pastor in 1986. In 1988, an extensive remodeling project was undertaken in anticipation of the 150th jubilee year. It was financed exclusively through parishioner donations, memorials and fund raisers. The completed church had refinished pews, a new altar, cleaned stained glass windows and additional seating space, among other improvements.

Father McKitrick retired from the priesthood in September, 2000. That same month, St. Patrick welcomed Father Stephen Potter as our new pastor. Unfortunately, a serious illness forced Father Potter to take a leave of absence that lead to his early retirement in 2004. During Father Potter's illness, Father Bernard Mullane, and later, Father John Slampak were administrators of the Parish until the arrival of Father Joseph P. Naill, in July, 2004.

Father Naill completed a restoration of our church that added an enclosed vestibule, a new confessional, restoration of the wood beams, among other improvements.

Father Joachim Tyrtania arrived in July 2010 and served until August 2011.

Father Godwin Asuquo arrived in August 2011 as parochial administrator and in August 2012 became pastor of St. Patrick Church. Fr. Godwin spearheaded the prayer garden and memorial brick project in 2014, celebrated our 175th sesquicentennial anniversary in August 2015 with a year of events such as stained glass window tours, golf outings, cemetery tour, back to school brunch, and Christmas caroling. In 2017, St. Patrick Church was given landmark status by the City of McHenry's landmark commision.  Fr. Godwin is the founder of ImaBridge Africa, a faith-based charity dedicated to building transformational relationships between the people of Nigeria and America with ten St. Patrick parishoners volunteering, eight St. Patrick parishioners serving as board members and 15 parishioners have travelled to Nigeria as a mission trip. Fr. Godwin has accompanied our St. Patrick family on eight pilgrimages over 12 years travelling to the Holy Land twice, Italy twice, Fatima, Ireland, Greece and Poland/Eastern Europe.  Finally, with extreme generosity from our parishioners, $1.3 million in debt was settled under Fr. Godwin's direction. Fr. Godwin served as pastor for 12 years until his reassignment by the Diocese of Rockford to St. Joseph Church in Aurora in June 2023.

Father Dario Endiape arrived as Parochial Administrator in June 2023.