The Archdiocese of Mexico is a Latin Church ecclesiastical territory or archdiocese of the Catholic Church that is situated in Mexico City, Mexico. It was erected as a diocese on 2 September 1530 and elevated to an archdiocese on 12 February 1546. The archdiocese is one of the largest in the world, with over four million Catholics, surpassed only by Kinshasa, Guadalajara, São Paulo, Puebla de los Ángeles, Santiago de Guatemala, and Milan.

Mexico, officially the United Mexican States, is a country in the southern portion of North America. It covers 1,972,550 km2, making it the world's 13th-largest country by area; with a population of almost 130 million, it is the 10th-most-populous country and the most populous Spanish-speaking country. Mexico is organized as a federal constitutional republic comprising 31 states and Mexico City, its capital. It shares land borders with the United States to the north, with Guatemala and Belize to the southeast; as well as maritime borders with the Pacific Ocean to the west, the Caribbean Sea to the southeast, and the Gulf of Mexico to the east.