Wonder Lake is a village in McHenry County, Illinois, United States. The population was 1,345 at the 2000 census, but by the 2010 census, the population had grown to 4,026.
Wonder Lake is located at 42°23′3″N 88°22′4″W (42.38427, -88.367814).
According to the 2010 census, Wonder Lake has a total area of 5.925 square miles (15.35 km2), of which 4.78 square miles (12.38 km2) (or 80.68%) is land and 1.145 square miles (2.97 km2) (or 19.32%) is water.
As of the census of 2000, there were 1,345 people, 445 households, and 367 families residing in the village. The population density was 1,657.4 people per square mile (641.1/km²). There were 488 housing units at an average density of 601.4 per square mile (232.6/km²). The racial makeup of the village was 97.17% White, 0.37% Black or African American, 0.07% Native American, 0.30% Asian, 1.12% from other races, and 0.97% from two or more races. Hispanic or Latino of any race were 4.46% of the population.
There were 445 households out of which 45.2% had children under the age of 18 living with them, 69.4% were married couples living together, 9.0% had a female householder with no husband present, and 17.5% were non-families. 12.8% of all households were made up of individuals and 3.8% had someone living alone who was 65 years of age or older. The average household size was 3.02 and the average family size was 3.32.