Algonquin is a village in McHenry and Kane counties, Illinois, in the United States. It is a suburb of Chicago, located approximately northwest of the Loop. As of the 2020 census, the village's population was 29,700. The village is known as "The Gem of the Fox River Valley", referring to the location of its downtown. Geography Algonquin is located in southeastern McHenry County and northeastern Kane County at (42.162741, −88.302571). It is bordered to the north by Lake in the Hills, to the northeast by Cary, to the east by Barrington Hills, and to the south by Carpentersville. As of the 2010 census, Algonquin had a total area of , of which (or 98.55%) were land and , or 1.45%, were water. Approximately 78% of the village area is in McHenry County, with the remainder in Kane County. Demographics 2020 census 2010 Census As of the census of 2010, there were 30,046 people, 10,247 households, and 8,170 families living in the village. The population density was . There were 10,727 housing units, of which 480, or 4.5%, were vacant. The racial makeup of the village was 87.2% White, 1.7% African American, 0.2% Native American, 7.3% Asian, 0.04% Pacific Islander, 1.8% some other race, and 1.7% from two or more races. Hispanic or Latino of any race were 6.8% of the population. Of the 10,247 households in the village, 44.6% had children under the age of 18 living with them, 69.3% were headed by married couples living together, 7.4% had a female householder with no husband present, and 20.3% were non-families. 16.4% of all households were made up of individuals, and 5.1% were someone living alone who was 65 years of age or older. The average household size was 2.93, and the average family size was 3.32. 29.0% of the village population were under the age of 18, 6.5% were from 18 to 24, 27.3% were from 25 to 44, 29.2% were from 45 to 64, and 8.1% were 65 years of age or older. The median age was 38.3 years. For every 100 females, there were 97.1 males. For every 100 females age 18 and over, there were 95.0 males. For the period 2013-2017, the estimated median annual income for a household in the village was $103,291, and the median income for a family was $115,111. Male full-time workers had a median income of $77,443 versus $56,544 for females. The