Saint Helena Cathedral. The Cathedral of Saint Helena is the cathedral of the Roman Catholic Diocese of Helena, Montana. Modeled by architect A.O. Von Herbulis after the Votivkirche in Vienna, Austria, the construction began on the cathedral in 1908, and held its first mass in November 1914.

Bishop John Patrick Carroll worked tirelessly to raise funds for building the cathedral and had an administrative role in management of the entire project. The cathedral sustained significant damage during the 1935 Helena earthquake, which required extensive renovations. The cathedral was added to the National Register of Historic Places in 1980.