Mendota is a city in LaSalle County, Illinois, United States, in the state's north-central region. The population was 7,061 at the 2020 census. It is part of the Ottawa, IL Micropolitan Statistical Area. Mendota is located approximately 85 miles west of Chicago, 70 miles east of Moline and 55 miles south of Rockford. The current mayor is David W. Boelk, an independent elected to a four-year term.

LaSalle County is located within the Fox Valley and Illinois River Valley regions of the U.S. state of Illinois. As of the 2020 Census, it had a population of 109,658. Its county seat and largest city is Ottawa. LaSalle County is part of the Ottawa, IL Micropolitan Statistical Area of Northern Illinois.