Coordinates: 42°17′46″N 91°00′58″W / 42.296°N 91.016°W
Saint Mary's Catholic Church is a former Roman Catholic parish located in the town of Cascade, Iowa. It was built to accommodate the German residents of the city, while the nearby Saint Martin's was established for the Irish residents.
The church featured Gothic architecture. It also featured a Wangerin-Weickhardt pipe organ. This organ was removed and is currently being restored. The organ will then be installed at Saint Martin's church.
In the mid-1990s Saint Mary's parish and Saint Martin's parish were merged into one parish known as St. Matthias. The parish initially had the two church buildings as worship centers. Eventually the parish decided to close Saint Mary's church. Saint Mary's church was relegated to profane use and sold. At the time the Cascade library considered moving into the church, but decided against doing so. An antiques store opened within the former church, and still operates today[update].