Kane County is a county in the U.S. state of Illinois. According to the 2020 census, it has a population of 516,522, making it the fifth-most populous county in Illinois. Its county seat is Geneva, and its largest city is Aurora. Kane County is one of the collar counties of the metropolitan statistical area designated "Chicago–Naperville–Elgin, IL–IN–WI" by the US census.

Geneva is a city in and the county seat of Kane County, Illinois, United States. It is located on the western side of the Chicago suburbs. Per the 2020 census, the population was 21,393.