O. Henry Hall, also or formerly known as the U.S. Post Office and Federal Building, is an historic building located at 601 Colorado Street in Austin, Texas. It is located within the Sixth Street Historic District in Downtown Austin.
It previously served as a post office and a courthouse for the United States District Court for the Western District of Texas. It is currently owned by the University of Texas, and serves as the administrative headquarters for the University of Texas System. The building was listed on the U.S. National Register of Historic Places in 1970.