what county is bethalto, il
Bethalto, Illinois. Homefacts City Report. Bethalto is located in Madison County, IL. The population is 9,506, making Bethalto the 9th largest city in Madison County. There are 5 public schools in Bethalto with an average Homefacts rating of C+. The total crime rate for Bethalto is low, and there are 8 registered sex offenders residing in the city.