Located in central St. Louis County, St. John is approximately 2 square miles of residential and commercial property, including multiple City and/or County parks. St. John is only a few miles south of Lambert-St. Louis International Airport, and offers quick and easy access to all of St. Louis County and St. Louis City via its two major thoroughfares, St. Charles Rock Rd. and Interstate I-170.
In addition to maintaining its own public works department and police force, St. John contracts police services to two surrounding municipalities, Sycamore Hills and Bel-Nor.