St. Mary's City Hall is located at 11 Lafayette Street, St Marys PA 15857.
The Borough of St. Marys was settled in 1842 by a group of German Bavarian Catholics intent on establishing a religiously and ethnically homogeneous colony in America. A site was chosen and land purchased in the wilderness of north central Pennsylvania. After clearing the area, the new settlement was founded on December 8, 1842, which was the Feast of the Immaculate Conception. In honor of the Blessed Mother, the colony was named Sanct Marien Stadt (or St. Marys). The Borough of St. Marys was incorporated on March 3, 1848, from portions of Ridgway Township.
The Township of Benzinger was also originally settled in 1842 and formally created on December 18, 1845, by the Elk County Commissioners. The ordinances of the Township were originally codified in 1987 by Penns Valley Publishers.
In July 1989, the elected officials of St. Marys Borough and Benzinger Township appointed a Joint Study Commission charged with assembling and studying all data pertinent to consolidation or other forms of cooperation between the communities. After careful analysis, the Commission presented its findings and recommendations at a joint meeting of the Borough Council and the Township Supervisors. Following the recommendations of the Joint Study Commission, the citizens of St. Marys Borough and Benzinger Township circulated petitions to have the question of consolidation placed on the November 5, 1991 ballot. The citizens overwhelmingly approved the consolidation of the Borough of St. Marys and the Township of Benzinger into a third class city to be known as the "City of St. Marys," the first municipal government consolidation in Pennsylvania since 1956.