O'Fallon is a city located in St. Charles County, Missouri, United States. It is part of the Greater St. Louis metropolitan area and is known for its family-friendly atmosphere, parks, and recreational facilities. The city has experienced significant growth in recent years, making it one of the fastest-growing cities in Missouri. The city offers a variety of amenities, including shopping centers, restaurants, and community events. O'Fallon is also home to several schools and educational institutions, contributing to its appeal for families. The nearby Missouri River provides opportunities for outdoor activities, enhancing the quality of life for residents.