Although the parish that today is recognized as St. Mary Star of the Sea dates from 1876, the story of Unionville Catholics seeking a place of worship goes back before this nation's Civil War. Father Luke Daily, from St. Mary's Church in New Britain, inaugurated services in Unionville in 1854 on the south side of the river in the Connolly residence, later known as the Curran home. Monthly masses were said in the old Merriman Hall, located near the present site of of the Unionville Famiy Restaurant. Father Daly was followed by a number of missionary priests who served the needs of area Catholics.
Finally, in the nation's centennial year, 1876, St. Mary Star of the Sea Church was officially established being formally incorporated into the Diocese of Hartford. A number of stories, none substantiated, exist as to the origin of the name. Incidentally, the cost of the original building was $30,000.
An early seating practice that characterized the congregation had the Slovak parishioners seated to the left of the main altar, the Irish to the right. The weekly prayer meetings of the Slovak Rosary Society honored the tradition by taking place in the left half of the Church.
For the first few years of its existence, St. Mary's functioned as a Mission Church, serviced by Father Bernard O'Reilly Sheridan, pastor in Collinsville. Although Father Patrick Fox, Father Sheridan's successor, was the first resident pastor of St. Mary's, his tenure in Unionville was brief. He did oversee the completion of the new church as well as the rectory. In contrast, the pastor who followed him, Father William Redding, served the parish longer than any other, from 1886-1919. During his stay, the rectory was enlarged and the church was rebuilt following a fire.
Father Thomas Tiernan, who followed as St. Mary's pastor, increased the size of the church and was responsible for finishing its basement. He in turn was succeeded in 1930 by Father John Sullivan, whose years in the parish closely coincided with those of the Great Depression, leaving in 1939. His greatest contribution to St. Mary's was putting the church's financial affairs in order and freeing it of its debt, no mean accomplishment during those difficult times. This accomplishment provided the groundwork for the accomplishments of St. Mary's "wartime pastor," Father John Walsh, who served from 1939 to 1945. It was he who planned the Veterans' Memorial in the cemetery, and he made certain that young men serving in the armed forces remained in touch with their home parish by sending to them pictures of the church.
His successor, Father John Connor served the community from 1945-1954 and purchased the parking lot property. Father Connor also saw the church almost go up in smoke in 1949 from a fire started by a child who had been playing with matches.
Father John Phalen succeeded Father Connor and served as pastor until 1967. He introduced the first liturgical changes to St. Mary's, the outgrowth of the Second Vatican Council that brought the English vernacular as the language of worship with commentators, lectors, the celebrant facing the congregation and greater participation in the service.
Next came the pastorate of Father James Noonan, who would continue the renovation of the church's interior to accommodate the new liturgy. During his time, the St. Mary's Parish Council came into existence, the Hart House was purchased, and the cemetery was expanded.
In more recent decades, the leaders of the St. Mary's have helped guide the community into a new era, one that involved a major change in the parish. Father Robert St. Martin aptly shepherded the community, followed by Father John Golas who was named as the pastor in 2000. Under their supervision, the decision was made for a new church to be built. This important and challenging effort was completed, with the new church building officially dedicated in 2004. After this successful work and time of transition, Monsignor Michael Motta was named as pastor in 2013.
After nearly a decade of successful ministry at St. Mary's, Monsignor Motta was able to retire, with Father Matthew Gworek beginning as pastor at the end of 2021. He was for a time assisted by Father Joshua Wilbur as Parochial Vicar and now works alongside Father Roberto McCarthy in that role, as the two serve at both St. Mary Star of the Sea Church and St. Patrick Church in Farmington.