The Roman Catholic Archdiocese of Dubuque (Latin: Archidioecesis Dubuquensis) is an ecclesiastical territory or diocese of the Roman Catholic Church in the northeastern quarter of the state of Iowa in the United States. It includes all the Iowa counties north of Polk, Jasper, Poweshiek, Iowa, Johnson, Cedar, and Clinton counties. It also includes the counties east of Kossuth, Humboldt, Webster and Boone counties.