The stained glass windows and sign from the original church have now been incorporated into the new church (replacing the plain windows in Saint Michael's Chapel), creating a blessed mix of the old and the new.

While early records of Saint Michael's are scarce, some information is known. In 1849, a mission congregation was formed by Roman Catholic Chaplains who accompanied French Regiments of soldiers from Canada and conducted Christian services in Southwestern Pennsylvania. As the number of Catholics increased in the area, a Father Gallager held services in the old Robert C. Walker residence opposite the Odd Fellows Hall and later at the home of William Lambert, where the Elizabeth Methodist Church now stands.

On May 5, 1851, Most Reverend Bishop Michael O'Connor (the first Bishop of the Diocese of Pittsburgh) purchased a lot in Elizabeth from John and Ann Walker. Following the construction of the building, the Church was dedicated under the invocation of the Archangel Saint Michael on September 28, 1851. In 1855, official baptismal and marriage records were begun by Reverend Richard Phelan (the fourth Bishop of the Diocese of Pittsburgh). Father Dennis Kearney became Pastor in 1861. In 1863, a brick house was purchased and used as the Parish rectory. In 1864, Father Kearney purchased a small tract of land, near the Church, to be used as a cemetery (Calvary Cemetery). A small school house was built on the cemetery grounds by Father William Hayes. However, shortly after being built, the school was closed when it became evident that the congregation maintained a slow, but study growth. The first Church Directory was published in the Herald on July 15, 1876. The Directory listed one Mass at 10:30 AM on Sunday and Vespers at 3:00 PM with Reverend Peter Garvey as the Pastor.

At the beginning of the Twentieth Century, when the steel industry began booming along Southwestern Pennsylvania's Rivers, many new towns and congregations were formed. This made it possible for the priests in Elizabeth to devote all of their time to the Saint Michael Parish Community.

In 1907, Father John Fallon called a meeting of Saint Michael's Parishioners to decide whether to enlarge the present church or build a new one. The Congregation decided to enlarge the church by thirty feet, sacristies on either side, the walls and tower was raised, the flat roof was replaced with an arched roof, lavatories were added to the basement and a meeting room, wainscoting presses for vestments and cassocks, and a steam heating plant was installed. Three alters were painted gold and cream and the crosses were painted gold. In order to make room for the expansion of the church, the bodies in the cemetery behind the church were disinterred and reinterred at the new parish cemetery, Calvary.

As the Parish grew and expanded from 100 families, Father Fallon purchased lots directly next to the church allowing the church to own the entire square. Father Fallon was very much an example of a "people's priest." He often visited parishioners while riding his bicycle about the town, countryside, and mining communities. Following Mass on Sundays, he would travel to Bunola to teach the children. Father Fallon encouraged social activities including boat excursions, parish picnics, and parish dances. Following Father Fallon's leaving to become pastor of St Canice in Knoxville. That same day, Father Michael Leen became pastor at Saint Michael's.

Father Leen continued the work of Father Fallon by teaching religion classes for the children of Bunola and added classes for the children of Calamity Hollow. Classes were also held for the children who lived within walking distance of the Church following the 8:30 am Mass on Sundays. In September of 1924, James McEllhatten organized a choir of male and female voices. The choir became very well-known and, subsequently, traveled to other parishes in the region for special occasions. The choir also put on concerts and donated the proceeds to various charities in the region. 

In 1932, a second renovation took place. The Church was lengthened again in order to make room for the growing congregation. Additional pews were added and the confessionals were moved up toward the front of the Church. Also, renovations were made to the rectory. Following his appointment as pastor, Father Thomas Sullivan conducted a parish census after learning about the wide-spread boundaries of the parish's reach and that many of the families were not in any database. After completion of the census, it was revealed that Saint Michael Parish served 591 families and 1,916 individuals.

Father Sullivan was concerned about the education of the children. He firmly believed that the Parish could not grow and prosper without the children being properly educated about their faith. On May 16, 1948, the first baccalaureate service was held for 25 graduates of the class of 1948. Following the interest shown in the educational program, in July of 1948 a small building was constructed for catechetical classes, which were taught by ten Sisters of Charity from Seton Hill.

As Saint Michael's continued to grow, Father Sullivan became aware that he needed an additional priest to care for the 2,000 parishioners. The Diocese granted Father Sullivan's request and Father John Bock was appointed as parochial vicar on July 22, 1948.

In 1951, a major renovation was undertaken and everything was removed from the Church. New, plain altars were constructed by the Drechsler brothers to replace the gothic design altars. Other renovations included new plaster, new pews, new flooring, updating of the santuary and sacristies, all new electrical wiring and fixtures, new confessionals, new balcony, new stairs, repairs to the windows and doors, and new sidewalks were poured around the church. Also, the 65 year-old pipe organ was replaced with a new Wurlitzer electric organ.

In 1951, Saint Michael's celebrated its 100th Anniversary as a Parish of the Diocese of Pittsburgh. The following year brought the arrival of Father Thomas Gearing. Father Gearing was responsible for helping Father Sullivan to realize the dream of building a Parish School. In September of 1955, the cornerstone of the school was laid and the construction of the building was begun. In September of 1956, the school opened for grades one, two, and three. A Sister of the Divine Redeemer was the first principal for the 133 students who were registered. Then, in 1958, permission was granted to add a third floor to the school building. Following the addition, a grade was added each year with the first eighth grade class graduating in 1962.

On March 15, 1986, the Diocese of Pittsburgh announced that Saint Michael Parish would relocate and build new parish facilities on McLay Drive in the Parish's current location. The first mass was said in the new church on December 5, 1987 and the building was officially dedicated on January 10, 1988.