St. Rita was established in 1936. Before the parish was founded, local Catholics had to travel to Homestead, Munhall or Braddock to attend Mass. For many years, they hoped to have a church of their own. In fact, on September 1, 1925, two local Catholics deeded property to the bishop to be used for a future parish to be named St. Rita.
The parish became a reality in 1936 when the Mission Confraternity of Christian Doctrine was given the responsibility for organizing the parish. The first meeting of the new parish occurred on July 19, 1936, to plan for organization of the parish and fund raising for a church. The parish rented the old Whitaker Fire Engine House to celebrate Mass until a church could be purchased or built. The first Mass was celebrated on October 18, 1936.
Shortly afterwards, a garage was purchased and renovated into a church. The first Mass in the new church was celebrated on March 7, 1937. On September 30, 1937, the parish became independent with the appointment of a resident pastor.
The church was remodeled around 1940 including the installation of pews. Due to the increase of population in the area after World War II, the congregation eventually outgrew its church. In 1955, construction began on a new combined church and school building on the land donated in 1925. The completed building was dedicated on May 22, 1959. The building included a temporary church on the first floor and classrooms on the second floor. The original church was converted into a parish hall. The old church building was eventually sold in the early 1970's.
About that time, the parish was prepared to build a permanent church. Ground for the new church was broken on December 15, 1975, and the completed church was dedicated on October 10, 1976.
With the turn of the century, trends in the Diocese of Pittsburgh began to reveal a decline in Mass attendance and sacramental participation. At the same time, the number of priests available for parish ministry also began to decline.
To address these challenges, Bishop David Zubik announced on April 12, 2015 a new diocesan initiative, On Mission for The Church Alive!, a consultative strategic planning process designed to foster viable, sustainable and vibrant parishes. As part of this process, the Bishop, in consultation with the faithful, began to consider new models of parish life based on pastoral needs, financial and temporal resources and available clergy.
In 2018, following the period of consultation, parishes were grouped together and served by a single clergy team to eventually form one new parish.
During this transition period, St. Rita Parish remained an independent parish while sharing clergy and staff and eventually publishing a joint bulletin with the other parishes. This ended on July 1, 2020 when St. Rita Parish merged with the parishes of St. Maximilian Kolbe Parish, Homestead/Munhall; the Duquesne parishes of St. Joseph and Christ the Light of the World; the West Mifflin parishes of Holy Trinity, Resurrection and St. Agnes; and St. Therese of Lisieux Parish, Munhall to form the new St. Thomas the Apostle Parish. As part of the merger St. Rita Church remained open as part of the new parish.
