St. Peters Rec-Plex is a state-of-the-art fitness facility. The building houses a full-size ice rink and an Olympic-sized pool with diving capabilities. The pool annually hosts the Missouri State Swimming Championships for both the boys and girls swim team. The 2004 Olympic diving trials took place at the Rec-Plex.
Also at the Rec-Plex is a food court, a weight room and many other amenities. Rec-Plex South, located just south of the main building, is home to two regulation-sized ice hockey rinks.
The building, constructed in 1994, is 236,000 square feet.