St. Mary Parish in Downs, Kansas, traces its origins to the late nineteenth and early twentieth centuries, when Catholic settlers in the area were served by visiting priests from nearby towns such as Cawker City. Like many rural communities in north-central Kansas, Downs did not initially have a resident pastor, and Mass and the sacraments were offered on a mission basis as clergy traveled between scattered settlements. As the Catholic population gradually became more established, the need for a permanent parish community grew.

In 1903, St. Mary Parish was formally established. The founding parishioners purchased a former Congregational church building, originally constructed in 1879, and adapted it for Catholic worship. This marked the beginning of an organized Catholic presence in Downs, although the parish continued to function as a mission, typically served by priests assigned to nearby parishes rather than having its own resident pastor.

Over the following decades, the parish remained small but steady, reflecting the agricultural character of the region. By the mid-twentieth century, parishioners recognized the need for a newer and more suitable church building. Fundraising efforts began in 1955, demonstrating the commitment of the local Catholic community despite limited numbers and resources. Ground was broken for a new church in 1967, and in 1969 the present St. Mary Church was completed and dedicated, replacing the earlier structure.

Throughout its history, St. Mary Parish has remained a mission parish within the Diocese of Salina, typically sharing clergy with other nearby communities. Despite its size, it has continued to serve as an important center of worship and community life for Catholics in Downs and the surrounding rural area, preserving a legacy of faith that dates back more than a century.