Dallas architect Bryan, active at the time with the design team on the Texas Centennial Exposition in Fair Park (DS91), designed the Spanish Renaissance facade in a simplified rendition of the Churrigueresque mode. The strong verticality is emphasized by thick piers, rather than engaged columns as might be found on eighteenth-century Spanish examples, rising to pinnacles breaking above the scrolled gable. At the four-stage corner tower, the upper two stages are open belfries, topped with a tiled dome. Prominent buttresses modulate the long nave, with round-arched windows in the walls between. The church became the cathedral of the new diocese created in 1986 by Pope John Paul II.
At the southwest corner of the extended campus, St. Gregory Cathedral School (St. Gregory Elementary School; 1946, Shirley Simons) at 500 S. College Avenue establishes its own identity with its Georgian styling.