St. Mary's Catholic Cathedral (Cheyenne, Wyoming)

Architects from the firm of Fisher and Lowery designed the building. The sandstone for the exterior was quarried at Iron Mountain, north of Cheyenne. The 135-by-70-foot  cathedral is in the Gothic Revival style and features two side galleries and a rear organ loft. The ceiling is supported by steel and concrete arches faced with oak.  The stained glass windows are donated memorials crafted in Europe. The large Madonna window in the organ loft was a gift of the Knights of Columbus. Parish records do not contain information about the artists or installation dates. In 1962, the parish added a structure east of the cathedral to house meeting and activity rooms.

St. Mary's Cathedral is the cathedral and parish church in the Diocese of Cheyenne located in Cheyenne, Wyoming, United States.

The parish was founded as St. John the Baptist in 1867 and erected a frame church. The congregation outgrew the small brick church and construction of the new cathedral began in 1906.