Johnsburg is a northwest suburban Chicago village in McHenry County, Illinois, United States. The population was 5,391 at the 2000 census.
The area was settled in the 1840s by immigrants from the Eifel region of Germany, predominantly the Mayen-Koblenz district (Kreis), who named the settlement after their church. In 1956, a small subdivision on shore of the Fox River incorporated as the Village of Sunnyside. Sunnyside then annexed the surrounding land in 1992 and renamed it Johnsburg.
Johnsburg is located at 42°23′9″N 88°14′9″W / 42.38583°N 88.23583°W / 42.38583; -88.23583 (42.385796, -88.235942).