Founded by the Sisters of St. Francis of Williamsville, at the request of the Bishop of Buffalo, the hospital provided services to all, especially the poor.

Mount St. Mary's Hospital joined Catholic Health on July 1, 2015.

[1] Mount St. Mary's includes: Staff includes nearly 200 physicians, more than 300 RNs and LPNs, and allied health professionals and numerous employees in supporting roles.

In all, Mount St. Mary's Hospital and Health Center employs more than 1,200 people and has about 250 volunteers.

It is also the only hospital in the Niagara area accredited by The Joint Commission.