Gustavo García-Siller was named Archbishop of San Antonio by Pope Benedict XVI on October 14, 2010. Installed as Archbishop on November 23, 2010 at St. Mark the Evangelist Church in San Antonio, TX, he succeeded Archbishop Jose H. Gomez as the 6th Archbishop of San Antonio.

He was appointed an auxiliary bishop of the Chicago Archdiocese on January 24, 2003 by Pope John Paul II, and ordained on March 19, 2003 by Archbishop of Chicago, Francis Cardinal George, O.M.I.

Born December 21, 1956 in San Luis Potosi S.L.P, Mexico to Gustavo García Suarez and Maria Cristina Siller de García, Archbishop García-Siller is the eldest of 15 children. He grew up sweeping floors and washing windows, among other responsibilities in the family furniture store, until he was 16 years old. He attended Colegio Motolinia Elementary School and graduated from Colegio Motolinia High School In San Luis Potosi. The archbishop received his Formator Certificate from Escuela de Verano Para Formadores. He earned a Masters Degree in Theology and Divinity from St. John's Seminary in Camarillo, California and received his Masters in Philosophy from Instituto de Filosofia, Guadalajara, Mexico. Archbishop García-Siller attended ITESO, a Jesuit University in Guadalajara, Mexico, where he earned his Masters in Psychology.

In 1975 Archbishop García-Siller professed as a member of the Missionaries of the Holy Spirit. He was sent to the United States by his order in 1980, where he worked closely with the immigrant community. He was ordained a priest on June 22, 1984 in Guadalajara, Mexico and became a citizen of the United States on December 15, 1998. His more than 35 years of priestly service has taken many forms, including ministering to communities with varied cultural backgrounds. While in California, he served in Fresno and at three parishes in the Los Angeles area. He also worked in Oregon for three years. Through those many years he gave Parish Missions to Catholic parish communities throughout the United States.

Much of the archbishop's work with his order involved the formation of the men of his religious order. From 1978 to 1980 he taught at INUMYC Minor Seminary in Guadalajara, Mexico and at the Institute for Philosophy in Guadalajara. He served as a formator and teacher at Institute of Philosophy in Guadalajara, Mexico from 1988 to1990. He was also Rector of the Missionaries of the Holy Spirit in Lynwood and Long Beach California (1990 - 1996) and held that same position at Mount Angel in Mount Oregon (1996-1999).

Archbishop García-Siller has held several leadership positions in his religious order. From 1999 to 2003 he served as Major Superior of the Missionaries of the Holy Spirit, administering an area that at that time included the United States and Canada. He was elected the order's Provincial in 2003.

In 2003, he was named auxiliary bishop of Chicago. In his new role, he served as Cardinal Francis George's liaison to the Hispanic community, and was assigned to Vicariate V, which covers the south side of Chicago and its southwest suburbs. This area includes 79 culturally diverse parishes.

On a national level, Archbishop García-Siller currently serves on a number of committees for the United States Conference of Catholic Bishops (USCCB)—the Cultural Diversity Committee on Hispanic Affairs, African American Affairs, Committee on Hispanics and the Liturgy, and the Committee on Migration (USCCB).  He also served as Chair of Region 7 of the USCCB, which includes Illinois, Wisconsin and Indiana and on the Committee on Consecrated Life.