The Roman Catholic Archdiocese of San Antonio had a self-reported 2018 population of 796,954, up from 728,001 in 2014.

[4] The archdiocese includes the city of San Antonio and the following counties: Val Verde, Edwards, Real, Kerr, Gillespie, Kendall, Comal, Guadalupe, Gonzales, Uvalde, Kinney, Medina, Bexar, Wilson, Karnes, Frio, Atascosa, and Bandera, and the portion of McMullen County north of the Nueces River.

Originally part of the Ecclesiastical Province of New Orleans, it was subsequently elevated on August 3, 1926, to a metropolitan archdiocese.

All of Texas' dioceses had been suffragan sees under San Antonio until December 2004 when Pope John Paul II created the new Ecclesiastical Province of Galveston-Houston and elevated the Archdiocese of Galveston-Houston to a metropolitan see.

[6] On October 14, 2010, Pope Benedict XVI appointed Gustavo Garcia-Siller as archbishop of the Roman Catholic Archdiocese of San Antonio.