The St. John Interparochial School campus is a one-block area in Plaquemine, LA, comprising the high school, middle school, and elementary buildings. The main office is in the middle school building. The campus includes the St. John Gym, Cafeteria, St. Clement of Rome Chapel, Jerome Dugas Athletic Building, and St. John Field House. Athletic facilities on-site are the High School Baseball Field, Softball Field, and a practice field. The ACE teachers' residence is the former St. Clement of Rome Rectory.

In 2019, the gym underwent renovations, and a perimeter fence enclosed the core campus areas. Renovations and updates are ongoing to continue meeting the needs of our students.