what county is schaumburg, il in
Homefacts City Report. Schaumburg is located in Cook County, IL. The population is 74,228, making Schaumburg the 5th largest city in Cook County. There are 14 public schools in Schaumburg with an average Homefacts rating of A. The total crime rate for Schaumburg is very low, and there are 18 registered sex offenders residing in the city.