St. John Nepumocene Neumann, bishop of Philadelphia, purchased land from Mr. Jacob Emmett on South George St. in the borough of York, PA in 1850 for the creation of a parish for the German-speaking people of that borough. The Rev. James F. Cotting S.J. of Conewago, Adams County, who had been ministering to the people, began the construction of the church on July 13, 1852 and laid the corner stone on July 25, 1852.

The first church, measuring 42' by 80', was completed by October 25, 1852 on which date the first Mass was offered. The new church was consecrated on July 25, 1853 by Bishop John Neumann.

In 1863, the Rev. Joseph Hamm built the first rectory, the two-story brick building adjoining the church. That building is still in use for classroom, meeting and office space.

Rev. George J. Pape was appointed pastor of St. Mary's Church in 1868. He constructed a larger and more substantial school building at the rear of the church. Through his efforts, the Sisters of the Third Order of St. Francis of Glen Riddle, Pennsylvania came to teach in the school.

Father Pape realized that the church built in 1852 would soon become too small to meet the needs of the growing congregation. The new church, much larger than the original one of 1852, was built over the exact spot of the old building. In order to hold services without interruption during the raising of the new structure, the old church was left standing while the outside walls and roof of the new church were erected. Services were held within the old place of worship without interruption. The first Mass in the new church was celebrated on December 14, 1884. On December 29, fifteen days later, Bishop Shanahan blessed two new bells, with John Mayer and Peter Pfeiffer as sponsors. These two bells joined the bell from the first church in the center steeple. The completed church cost about $47,000 and had seats for 850. It was dedicated on Whit Monday, May 25, 1885.

Rev. George Seubert became the next pastor in 1902. Under Father Seubert, the interior of the church was frescoed. In 1905 he purchased the property at 309 S. George St. for a rectory. This house was built sometime during the Colonial period and is among the historic buildings of York. The Marquis de Lafayette visited York in 1825 and was entertained in this house.

Rev. George J. Breckel became the pastor of St. Mary's on November 21, 1907. During the year 1914, the exterior of the church was entirely refaced with port Deposit granite, the three steeples were rebuilt and trim of Indiana limestone finished the facing. The church was rededicated on December 13, 1914, the day of the celebration of the feast of the Immaculate Conception.

In 1921, the interior of the church was completely renovated. The existing floors, pews, wainscoting and sanctuary furnishings were removed. Marble altars, statues, floors, and wainscoting, new Stations of the Cross, pews, and sanctuary furnishings were installed. The high altar stood out prominently. On the two sides were the altars of the Blessed Virgin and Saint Joseph. The three altars were all of Italian marble from the Pietrasanta quarries. The base of the tabula of the main altar was sculpted from one piece of marble, with an extraordinary reproduction of Leonardo da Vinci's "Last Supper". The Right Rev. Philip R McDevitt consecrated the newly remodeled church, free from financial encumbrance, on July 16, 1921.

Ground was broken for a new building on May 12, 1927. This structure had the double purpose of serving as a recreational center and a school with several large classrooms and a spacious auditorium. The auditorium is located on the first floor and a gymnasium with a running track is located on the second floor. Four bowling alleys are located in the basement.

During 1951-52, in preparation for its centenary observance, an extensive remodeling program was completed which included redecorating, cleaning of marble and installation of new lighting and sound system. This was the third remodeling of the church.

On July 10, 1952, bishop George L. Leech of the Diocese of Harrisburg presided at a Solemn High Mass marking the 100th anniversary of the founding of Immaculate Conception parish. More than 100 priests attended and the priests' choir of the Harrisburg diocese sang the Mass. Prior to the Solmen High Mass, Msgr. Breckel celebrated a Requiem Mass at 8:00am in memory of the deceased priests, sisters and laity of the parish.

Msgr. Breckel retired as pastor in 1953 after serving an amazing 46 years. He was succeeded by Msgr. Harold E. Keller who served as pastor until his death in 1967.

Msgr. Leo Bierschmidt succeeded Msgr. Keller as pastor. During his tenure, in 1970, the church purchased the Wagman Machine Shop located behind the church. This area was later used to provide increased parking and playground facilities.

Father Joseph Klespis returned to St. Mary's in August 1971 having been assigned here after his ordination in 1955. In 1975, the properties on South Duke Street, which were adjacent to the machine shop property and a house on East College Avenue were purchased and demolished to create more parking space and a larger playground.

A new heating plant was constructed in January 1977. The 125th anniversary was celebrated on October 15, 1977. It began with the blessing and dedication of the parking plaza and the heating facility, as well as the completely renovated Pomplitz organ.

In 1986 a $100,000 project was undertaken to restore and renovate the front exterior of the church building under the leadership of Rev. Joseph B. Zednowicz, church pastor. The program included the restoration of the stone facade and steps, and the replacement of the choir loft floor. The century-old bells of St. Mary's were electrified in 1992. After being silent for many years, the bells were rung at Midnight Mass on Christmas, 1992.

The 1950's saw the influx of Spanish speaking peoples into York County to such an extent that Bishop George Leech appointed Rev. Andre Meluskey to minister to them. St. Mary's gave the community the use of one of its properties on South George Street and with the help of several Spanish families, the "Centro Hispana Catolico" was opened. The Hispanic population continued to grow over the next two decades and in 1979, the diocese acquired the former Annunciation Greek Orthodox Church on East South Street and established Cristo Salvador parish under the pastorship of Rev. Bernardo Pistone. After several restoration projects and the generosity of other parishes in the area, the church was fully functional in 1980.

In 1995, due to the diminished availability of priests, the Diocese of Harrisburg ended the existence of St. Mary's as a German national parish and formed a new St. Mary's along with the people of Cristo Salvador as a multi-lingual, territorial parish. The pastor appointed to this "new" parish was Father Lawrence Hemler. Deacon Catalino Gonzalez, from Cristo Salvador, became pastoral assistant.  In addition to being the first pastor of St. Mary's as a territorial parish, Fr. Hemler founded St. Mary's Thrift Shop, a valuable ministry to the community as well as an important source of income for the parish.  In June 1999, Fr. Hemler was succeeded by Rev. Robert M. Gillelan. 

The parish celebrated its 150th anniversary in 2002 with extensive remodeling and renewal. Of particular note was the discovery of the original 1921 Frederick Henwood mural series detailing the life of the Blessed Virgin Mary; these murals were covered over with Liturgical Movement style artwork during the 1952 church renovation. These paintings were restored by the hand of Mrs. Nancy Stamm. In 2004 the church was air conditioned and in 2009 the pipe organ was renovated and restored by the firm SDG Organs of Millersville, PA. 

Fr. Gillelan guided the church for thirteen years, until June 2012 when he was named Vicar General of the Diocese and was succeeded as pastor by Fr. Jonathan P. Sawicki. In August 2014, Father Sawicki was appointed Dean of the York Deanery by Bishop Gainer. He follows in the footsteps of Msgr. Breckel, Msgr. Keller and Fr. Gillelan who all served in this same capacity during their years at St. Mary's. During Fr. Sawicki's pastorate the parish continued to grow in numbers and holiness. The construction of an Atrium which connects the Church and School buildings and provides handicapped access and facilities was just one of the many improvements which Fr. Sawicki oversaw. In March 2019 Fr. Sawicki was appointed Director of Vocations for the Diocese of Harrisburg. At that time Bishop Gainer named Fr. John Kuchinski as our new pastor. Fr. Kuchinski was installed on June 29, 2019 and continues the tradition of faithful, holy men who have shepherded the flock of St. Mary's. 

St. Mary's Church is a vibrant multicultural community of faith, striving to be the shining presence of Christ in downtown York, Pennsylvania.