Genoa is a city in the north-east corner of DeKalb County, Illinois, United States. It is located on the historic Galena-Chicago stagecoach route. At the 2010 census the city had a population of 5,193, up from 4,169 in 2000.
Genoa was settled as early as 1835 by Thomas Madison, an American Revolutionary War soldier from Ashtabula County, Ohio. He named Genoa after a town of the same name in New York. Genoa was incorporated as a village in 1876 and as a city on September 9, 1911.
According to the 2010 census, Genoa has a total area of 2.655 square miles (6.88 km2), of which 2.6 square miles (6.73 km2) (or 97.93%) is land and 0.055 square miles (0.14 km2) (or 2.07%) is water.
As of the census of 2000, there were 4,169 people, 1,555 households, and 1,119 families residing in the city. The population density was 2,178.8 people per square mile (842.8/km2). There were 1,597 housing units at an average density of 834.6 per square mile (322.8/km2). The racial makeup of the city was 95.27% White, 0.14% African American, 0.19% Native American, 0.29% Asian, 0.02% Pacific Islander, 3.14% from other races, and 0.94% from two or more races.