Mater Dolorosa was founded in 1875. The establishment of the parish can be attributed to the discovery of oil in the area in the early 1870's. Before that time, the area was a farming area with a small Catholic population. The local Catholics usually traveled to St. Patrick, Sugar Creek or St. Joseph, North Oakland for Mass, although the pastors of St. Patrick made occasional visits to the area.
With the discovery of oil, the local population exploded. In 1873, the pastor of St. Patrick began offering Mass weekly in an old log school house. The next year, the bishop authorized the building of a church and in 1875 land was purchased for that purpose. The new church was dedicated on November 7, 1875. Within a year, the population had grown to the point that the parish considered building an addition to the church. Before anything could be done, oil production began to decline and the population dropped rapidly.
From 1875 until 1924, Mater Dolorosa was a mission of St. Patrick, Sugar Creek. In 1924, the parish became independent with the assignment of a resident pastor. The church was renovated in 1925 and enlarged in the 1930's. In 1951, St. James, Petrolia became a mission of Mater Dolorosa. In 1968 St. James was merged with Mater Dolorosa.
By the 1960's, it became obvious that the old church would have to be replaced. Ground was broken for the new church on July 25, 1965. The cornerstone was laid on September 25, 1966 and the completed church was dedicated on November 24, 1967.
In 1993, because of a shortage of priests in the diocese, the pastor of Mater Dolorosa also became the administrator of St. Joseph, North Oakland. Although both parishes remained independent, the same priest has responsibility for both congregations.
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, Mater Dolorosa Parish remained an independent parish while sharing clergy and staff and eventually publishing a joint bulletin with the other parishes. This ended on January 4, 2021 when Mater Dolorosa Parish merged with St. Joseph Parish, North Oakland and St. Wendelin Parish, Carbon Center to form the new St. Clare of Assisi Parish. As part of the merger Mater Dolorosa Church remained open as part of the new parish.