Moline is a city located in Rock Island County, Illinois, United States. With a population of 41,654 in 2024, it is the largest city in Rock Island County. Moline is one of the Quad Cities at the confluence of the Rock and Mississippi rivers, along with neighboring East Moline and Rock Island in Illinois and the cities of Davenport and Bettendorf in Iowa. The Quad Cities had a population of about 380,000 in 2023.