Collinsville is a city located in Madison County, Illinois, United States. It is part of the Greater St. Louis metropolitan area. The city has a population of around 24,700 people as of the 2020 census. Collinsville is known for its iconic landmark, the World's Largest Catsup Bottle, as well as its annual Cahokia Mounds Art Fair, Italian Fest, and Horseradish Festival. The city is home to various attractions, including the Gateway Convention Center, Willoughby Heritage Farm & Conservation Reserve, and the Collinsville Aqua Park. Collinsville also has a rich history, with traces of Native American settlements dating back to ancient times. The city has a diverse community and offers various recreational and cultural activities for residents and visitors.