Waterloo
Map
![Waterloo location map](https://tzmedia.b-cdn.net/media/images/static-maps/us/38_3419_-90_1509.jpg)
Map
![Waterloo location map](https://tzmedia.b-cdn.net/media/images/static-maps/us/38_3419_-90_1509.jpg)
Facts and practical information
Waterloo is a city in and county seat of Monroe County, Illinois. The population was 9,811 at the 2010 census. ()
Waterloo is a city in and county seat of Monroe County, Illinois. The population was 9,811 at the 2010 census. ()