Geneva is the county seat of Kane County, Illinois. It is an affluent suburb of Chicago. As of the 2000 census, the city had a total population of 19,515. Geneva is part of a tri-city area, along with St. Charles and Batavia. The area is currently experiencing a high level of population growth as Chicago's urban sprawl spreads farther west

According to the United States Census Bureau, the city has a total area of 8.6 square miles (22.2 km²), of which, 8.4 square miles (21.8 km²) of it is land and 0.2 square miles (0.5 km²) of it is water. The total area is 2.10% water.