Ridgefield is an unincorporated community and census-designated place in McHenry County, Illinois, United States. Ridgefield is 3 miles (4.8 km) northwest of Crystal Lake. It was named a CDP prior to the 2020 census which showed 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. Metra commuter trains pass through Ridgefield on their way to Chicago from Woodstock, Illinois without stopping, though there are currently shelved plans to build a station here.