Seneca is located in Lasalle County, IL. The population is 2,476, making Seneca the 9th largest city in Lasalle County.
There are 3 public schools in Seneca with an average Homefacts rating of B+. The total crime rate for Seneca is low , and there are 0 registered sex offenders residing in the city. Unemployment in Seneca is very high and the median home sales price is $0. Detailed and up-to-date Seneca property reports are available for any property address.
Cities near Seneca include Brookfield Township, Marseilles and Manlius Township.