The Diocese of Tucson is a Latin Church ecclesiastical territory – or diocese – of the Roman Catholic Church in southern Arizona in the United States. It is a suffragan diocese of the ecclesiastical province of the metropolitan Archdiocese of Santa Fe.

The Archdiocese of Santa Fe is a Latin Church ecclesiastical territory or diocese of the southwestern region of the United States in the state of New Mexico. While the mother church, the Cathedral Basilica of St. Francis of Assisi, is in the city of Santa Fe, its administrative center is in the city of Albuquerque. The Diocese comprises the counties of Rio Arriba, Taos, Colfax, Union, Mora, Harding, Los Alamos, Sandoval, Santa Fe, San Miguel, Quay, Bernalillo, Valencia, Socorro, Torrance, Guadalupe, De Baca, Roosevelt, and Curry. The current archbishop is John Charles Wester, who was installed on June 4, 2015.