Waterloo is located in Monroe County. About 11,013 people live here (as of 2020). Between 2010 and 2020, the population grew from 9,811 to 11,013. The region is at 219 meters above sea level. The area covers about 21.4 square kilometers. There are about 386 streets in Waterloo. The region was founded in 1818. The postal codes are 62298. The dialing code is 618. Waterloo is city in Monroe County, Illinois, USA. Among other things, Waterloo has public Transport, restaurants, schools and banks. More information at
www.waterloo.il.us.