On November 3, 1940, congregants of Saint Mary's Byzantine Catholic Church attended their first Divine Liturgy in a white wooden church of the Episcopalian Diocese of Pittsburgh. At that time, a rectory was purchased at a location three properties south of the church. The founding pastor, Father Gregory Moneta, remained there for ten years. Several pastors served the parish over the next six years.

Father Louis Sismis became pastor in 1956. In that year, the Pirohi Sales Project began as the parish fund-raising activity. In 1960, plans for the construction of a new church began.

In 1962, Father Joseph J. Borodach became the Temporary Administrator. On June 20, 1962, Bishop Nicholas T. Elko broke ground for the construction of the new church. He returned on March 17, 1963 to set the cornerstone, and on August 25, 1963 to solemnly bless and dedicate the new church, hall, rectory, and detached bell tower.

Monsignor Edward V. Rosack became pastor in 1973. He founded a successful pirohi project, a Holy Name Society, a Senior Rosary Society, and a School of Religion, which met on Saturday mornings. During Monsignor Rosack's pastorate, the School of Religion added a two-week Summer School in June, a choir was formed, the altar boys' sacristy was converted into a chapel for the daily celebration of the Liturgy, the American Bridge Company parking lot (across Park Road from the church) was purchased, a handicap-accessible ramp was installed, the bell tower was repainted, and a peaked roof was installed on the rectory.

The most recent physical improvements were completed in 1998, when an extension was built onto the rear of the church building and the entire interior of the church was renovated.

With Monsignor Rosack's retirement in June 2004, Father Thomas Schaefer was appointed administrator of St. Mary Church. During his pastorate, an icon screen was installed along with other church renovations to both the inside and outside of the church. In October 2006, Father Kevin E. Marks was appointed to the parish.