The Archival collections contain official records of Catholic Theological Union and its administrative offices, records of the academic departments and faculty committees, institutional publications, as well as personal papers and memorabilia pertaining to CTU and its programs and people. Other noteworthy collections are included in the CTU Archives when they support and relate to the mission and goals of Catholic Theological Union.

The Archives are open by appointment, and basic descriptions of some collections can be found in the library catalog, and some collections also have finding aids available. In addition, an online exhibit of digitized materials selected from both the archives and the library has been created to provide a platform for exploring digitization projects for the future.