Mendota is a city located in north-central Illinois in LaSalle County, Illinois, United States. The population was 7,372 at the 2010 census, and was estimated to be 7,327 by July 2013. It is the fifth largest city in LaSalle County and is part of the Ottawa-Peru, IL Micropolitan Statistical Area. Mendota is located approximately 70 miles east of Moline, Illinois, and 55 miles south of Rockford, Illinois. The current mayor is David W.