St. Louis (/seɪnt ˈluːɪs, sənt ˈluːɪs/) is the 2nd most populous city in Missouri, United States. It is located near the confluence of the Mississippi and the Missouri rivers. In 2020, the city proper had a population of 301,578, while its bi-state metropolitan area, which extends into Illinois, had an estimated population of over 2.8 million. It is the largest metropolitan area in Missouri and the second largest in Illinois. The city's combined statistical area (CSA) is the 20th largest in the United States