St. Peters is a city in St. Charles County, Missouri, United States. The official population estimate was 54,839 as of 2006. Interstate 70 passes through the city, providing a major transportation link. The 'Rec-Plex' in St. Peters is an award-winning recreation and fitness complex, now undergoing an $18.5 million expansion. The city also hosts the county's largest shopping center, Mid Rivers Mall, which plans a 120,000 sq. ft. expansion. St. Peters apartments for rent comparison page shows most up to date rent information on St. Peters apartments and houses. Rent information is obtained from multiple rental sources but we cannot guarantee their accuracy.