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.

When the drawings were presented, the Building Committee chose the Gothic form; a motion to authorize that design passed unanimously.

On November 8, 1914, the Catholic community of Helena gathered to celebrate Mass for the first time in the new church,[4] and the first funeral held in the cathedral was that of Thomas Cruse, a benefactor, December 26, 1914.

The restoration was completed in April 1959 in time for the golden jubilee of the cathedral and the 75th anniversary of the Diocese of Helena.

The upper-level renovation included the sanctuary, Saint Joseph's Chapel, new baptistry, and the installation of the elevator in the north transept for improved access between levels.

Physical plant enhancements include a new heating system, a renovated chime system, a renovated and enhanced pipe organ, the restoration of the stained glass and re-covering of their exterior surfaces, the installation of a new sound system, the construction of a new confessional, the removal of the old St. Helena Grade School, the construction and landscaping of a new main parking lot, and the exterior upgrade to the Faith Formation/Office building.

[7] The interior of the cathedral boasts 11,693 square feet (1,086.3 m2) of stained glass across 59 windows, which depict various scenes from the Old and New Testament.