The Cathedral of the Most Blessed Sacrament is a Neo-Gothic style Roman Catholic cathedral church in the United States. It is the seat of the archbishop of the Roman Catholic Archdiocese of Detroit. The metropolitan archdiocese for the Roman Catholic Ecclesiastical Province of Detroit includes all dioceses in the state of Michigan; in addition, in 2000 the archdiocese accepted pastoral responsibility for the Roman Catholic Church in the Cayman Islands, which consists of Saint Ignatius Parish on Grand Cayman. The cathedral is located at 9844 Woodward Avenue in Detroit, Michigan, adjacent to Detroit's Boston-Edison Historic District. The cathedral was listed on the National Register of Historic Places in 1982.

The Archdiocese of Detroit is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church covering the Michigan counties of Lapeer, Macomb, Monroe, Oakland, St. Clair, and Wayne. It is the metropolitan archdiocese of the Ecclesiastical Province of Detroit, which includes all dioceses in the state of Michigan. In addition, in 2000 the archdiocese accepted pastoral responsibility for the Catholic Church in the Cayman Islands, which consists of Saint Ignatius Parish on Grand Cayman.