St. Thomas sits on seven acres in a quiet Coral Gables neighborhood. The parish has two large connected buildings with a courtyard in the center. The classroom building includes 33 classrooms, the library-media center, dance studio, and school and church offices. The Roger M. Tobin Building includes Rantz Hall (parish hall/performing area), music room, language lab, environmental science room, learning resource center, art room, meeting/conference rooms, and offices.
The campus has two fenced playfields, basketball court, preschool playground with shade structures, covered outdoor lunch area, parking lot, walking paths, and gardens.