The diocese consists of the counties of Bastrop, Bell, Blanco, Brazos, Burleson, Burnet, Caldwell, Coryell, Falls, Hamilton, Hays, Lampasas, Lee, Limestone, Llano, Mason, McLennan, Milam, Mills, Robertson, San Saba, Travis, Washington, and Williamson.

The first Catholic mission in Texas, then part of the Spanish Empire, was San Francisco de los Tejas.

During his tenure, Reicher built or restored over 200 churches and facilities, including a chancery office, Holy Cross Hospital in East Austin, Texas, Newman Centers on five college campuses, and six church-sponsored, low-rent housing projects.

[8] In 1964, Reicher transferred all of his personal wealth, approximately $5 million, to a trust fund providing direct assistance to the poor and sick along with low-interest loans to church institutions.

After returning to Austin, he established the Office of Black Catholics to focus on African American ministry within the diocese.

McCarthy established the Diocesan Law Project, which recruited hundreds of attorneys and interpreters to volunteer legal services for the needy.

The diocese grew rapidly (partly as a result of immigration) during Aymond's tenure and actually had more churchgoers than many archdioceses, including New Orleans after Hurricane Katrina.

Reverend Dan Delaney in 2003 was accused by a man of sexually abusing him in a hotel during a youth trip when he was a child.

[15] In March 2016, a man sued the diocese for $1 million, claiming that he had been sexually abused by Reverend Milton Eggerling during the 1970's.

The plaintiff said that Eggerling gave him alcohol and took him on special trips, and that the staff at St. Louis Church and School did nothing to intervene.

[19] In July 2020, three women, including the woman in hospice care who recovered, sued the diocese, claiming they were groped by Langsch.

[22] In January 2019, the Diocese of Austin released a list of 22 clerics with credible accusations of sexual abuse of minor.

[25] The Central Administrative Office of the diocese showed revenues of $37.0 million for the fiscal year ending June 2022.