The history of the Catholic Church in Texas began with the arrival of Spanish explorers and missionaries in the 16th Century. Missions throughout Texas and the southwest were established by Franciscan friars for the care of souls. Following the Texas War of Independence in 1836, Catholics found themselves cut off from Church authorities in Mexico and appealed to Rome for assistance. In response to these appeals, Pope Gregory XVI designated Texas as an Apostolic Prefecture in 1839 with Father John Timon, C.M. as Prefect Apostolic. Father Jean Marie Odin, C.M., was named the Vice Prefect.

When Father Odin arrived in Texas in 1840, there were five parishes for the entire state serving 12,000 Catholics. Soon settlers from the United States, France, Germany, Ireland, Italy, Poland and all other parts of Europe came to Texas. In 1842, Pope Gregory XVI raised the Prefecture of Texas to the level of a Vicariate Apostolic and Father Odin was ordained a bishop to care for the Vicariate. Five years later in 1847, Pope Pius IX created the Diocese of Galveston with The Right Reverend Jean Marie Odin, C.M. as the first bishop. The diocese was dedicated to the Blessed Virgin Mary, under the title of her Immaculate Conception and St. Mary's Church in Galveston was named as the Cathedral.

The Diocese of Galveston, which encompassed the entire state of Texas, was ministered to by Bishop Odin and ten priests. Bishop Odin continued to serve the Diocese of Galveston until 1861, when he was named Archbishop of New Orleans. He was succeeded by the Right Reverend Claude Marie Dubuis, who like Bishop Odin was a native of France. Bishop Dubuis saw the diocese through the turmoil of the Civil War years. Following the war, additional parishes, hospitals and schools were established throughout the diocese. In 1874, the Diocese of Galveston was split when the western half of the State of Texas was established as the Diocese of San Antonio. This first division was a sign of the growth of the Church in Texas.


Upon Bishop Dubuis' retirement to France in 1881 due to poor health, the Right Reverend Nicholas A. Gallagher became the Apostolic Administrator and later the third Bishop of Galveston. Under his guidance, the diocese continued to grow and additional priests and religious were invited to serve in the area. At the time of his death in 1918, there were over 70,000 Catholics and 120 parishes.      

Succeeding Bishop Gallagher was Bishop Christopher Byrne who served as bishop for 32 years. During his episcopacy, the Diocese of Austin was created and Houston began to grow dramatically. The number of churches in Houston grew from eight to twenty-eight and the number of Catholics in the diocese increased from 70,000 to 250,000.       
Bishop Byrne was followed by the Most Reverend Wendelin J. Nold, the first native Texan to be bishop of the diocese. Throughout Bishop Nold's administration, he stressed Catholic education. Catholic High schools were built as well as new facilities for St. Mary's Seminary, which was founded in La Porte in 1901. In 1959, the diocese was re-designated as the "Diocese of Galveston-Houston" and Sacred Heart Church in Houston was named the Co-Cathedral. This change reflected the growth of the Houston area. With the re-designation of the diocese, a new chancery building was built in Houston and the administrative offices were transferred there in 1963.

Due to progressive blindness, Bishop Nold was prompted to resign from the administration of the diocese. Bishop John L. Morkovsky, Bishop of Amarillo, was named as a Coadjutor Bishop and Apostolic Administrator of the diocese in 1963. Upon Bishop Nold's retirement in 1975, Bishop Morkovsky, who had seen the diocese through the changes of Vatican II, succeeded him as the sixth bishop of the Diocese. Texas continued to experience tremendous growth which led to further divisions of the diocese, including the Dioceses of Beaumont (1966), Victoria (1982) and Tyler (1987). Bishop Morkovsky served the diocese until he retired in 1985, when he was succeeded by Bishop Joseph A. Fiorenza, Bishop of San Angelo.      


 Bishop Fiorenza, the first native of the diocese to serve as the diocesan Bishop, shepherded over 1,200,000 Catholics. The Diocese of San Antonio, created from the original Diocese of Galveston in 1874, was created an Archdiocese in 1926. By 2004, there were fifteen dioceses in Texas, making the Texas province the largest in the world. On December 29, 2004, Pope John Paul II created a second archdiocese in Texas, raising the Diocese of Galveston-Houston to the status of a Metropolitan Archdiocese. Archbishop Fiorenza was named the first Archbishop of Galveston-Houston, and Bishop Daniel DiNardo the Coadjutor Archbishop. 

Archbishop DiNardo became ordinary of the Archdiocese upon Archbishop Fiorenza's retirement in 2006.Pope Benedict XVI elevated Archbishop DiNardo to the position of Cardinal on Nov. 24, 2007. Previous auxiliary bishops have been the late Bishop John McCarthy, the late Bishop Enrique San Pedro, S.J., and Bishops Curtis J. Guillory, S.V.D., James Tamayo, Vincent M. Rizzotto and Joe S. Vasquez.