Ridgefield is an unincorporated community and census-designated place in McHenry County, Illinois, United States. Ridgefield is 3 miles northwest of Crystal Lake. It was named a CDP before the 2020 census, at which time it had a population of 210. Ridgefield hosts a small number of antique shops in a small crossroads business district. Ridgefield also has a large grain storage facility and a retail hardware store.