Frederick Xavier Katzer was an Austrian-born prelate of the Catholic Church. He served as bishop of the Diocese of Green Bay in Wisconsin (1886–1891) and archbishop of the Archdiocese of Milwaukee in Wisconsin (1891–1903).

The Roman Catholic Diocese of Green Bay is a Latin church diocese in the northeast region of Wisconsin in the United States. It is a suffragan diocese of the Archdiocese of Milwaukee. Its mother church is the Cathedral of Saint Francis Xavier in Green Bay.