St. Malachy was established in 1947 as a mission of the Missionary Confraternity Of Christian Doctrine (MCCD). The diocese formed the MCCD to bring religious instruction to Catholics living in small, isolated communities who did not have easy access to an existing church.
Before St. Malachy became a mission, local Catholics attended St. Francis de Sales in McKees Rocks. In 1946, the pastor of St. Francis de Sales met with Catholics living in Kenmawr to discuss the possibility of their establishing their own church. They later met with the director of the MCCD, who agreed to form a mission. The MCCD began with a Sunday School, which started in two private homes on March 16, 1947. The first Mass to be celebrated in Kenmawr took place in a private home on April 13, 1947. Beginning on June 8, 1947, Mass was transferred to a leased cottage.
In 1949, land was purchased for a future church and school. On February 25, 1953, the mission was raised to the status of a parish and a resident pastor was assigned. On August 16, 1953, ground was broken for a combined church and school building. The cornerstone of the new building was laid on May 9, 1954, and the completed building was dedicated on June 19, 1954.
The congregation continued to grow. In the mid-1960's, a fund raising campaign for a new church began. Ground for the church was broken in May of 1968 and the completed church was dedicated on April 22, 1972.
Office hours vary, but the church has mass weekdays at 7:15 a.m.; Saturday at 4:00 p.m. and twice on Sunday, 8:00 a.m. and 11:00 a.m.
Free, on-site parking is available.