Will County is located in the northeastern part of the state of Illinois. According to the 2020 census, it had a population of 696,355, an increase of 2.8% from 677,560 in 2010, making it Illinois's fourth-most populous county. The county seat is Joliet. Will County is one of the five collar counties of the Chicago metropolitan area. The portion of Will County around Joliet uses area codes 815 and 779, while 630 and 331 are for far northern Will County and 708 is for central and eastern Will County.

History Will County was formed on January 12, 1836, out of Cook and Iroquois Counties. It was named after Conrad Will, a politician and businessman involved in salt production in southern Illinois."Was Dr. Conrad Will really worth his salt?" , Ledger-Sentinel, Roger Matile, June 22, 2006 Will was a member of the first Illinois Constitutional Convention and a member of the Illinois legislature until his death in 1835. The county originally included the part of Kankakee County, Illinois, north of the Kankakee River. It lost that area when Kankakee County was organized in 1852. Since then its boundaries have not changed.

36 locations in Will County are on the National Register of Historic Places.

Geography According to the U.S. Census Bureau, the county has an area of , of which is land and (1.5%) is water.

The Kankakee River, Du Page River and the Des Plaines River run through the county and join on its western border. The Illinois and Michigan Canal and the Chicago Sanitary and Ship Canal run through Will County.

A number of areas are preserved as parks (over total) under the Forest Preserve District of Will County. The Midewin National Tallgrass Prairie is a U.S. Forest Service park in the county on the grounds of the former Joliet Arsenal. Other parks include Channahon State Park and the Des Plaines Fish and Wildlife Area.

Climate and weather

In recent years, average temperatures in the county seat of Joliet have ranged from a low of in January to a high of in July, although a record low of was recorded in January 1985 and a record high of was recorded in June 1988. Average monthly precipitation ranged from in January to in July.

Adjacent counties Kane County (northwest) DuPage County (north) Cook County (northeast) Lake County, Indiana (east) Kankakee County (south) Grundy County (southwest) Kendall County (west)

Demographics

2020 census

As of the 2020 census, the county had a population of 696,355. The median age was 39.0 years. 24.5% of residents were under the age of 18 and 14.1% of residents were 65 years of age or older. For every 100 females there were 97.6 males, and for every 100 females age 18 and over there were 95.6 males age 18 and over.

The racial makeup of the county was 63.7% White, 11.6% Black or African American, 0.6% American Indian and Alaska Native, 6.2% Asian, <0.1% Native Hawaiian and Pacific Islander, 7.8% from some other race, and 10.1% from two or more races. Hispanic or Latino residents of any race comprised 18.8% of the population.

95.1% of residents lived in urban areas, while 4.9% lived in rural areas.

There were 240,009 households in the county, of which 37.3% had children under the age of 18 living in them. Of all households, 58.1% were married-couple households, 14.2% were households with a male householder and no spouse or partner present, and 22.0% were households with a female householder and no spouse or partner present. About 20.3% of all households were made up of individuals and 8.9% had someone living alone who was 65 years of age or older.

There were 250,678 housing units, of which 4.3% were vacant. Among occupied housing units, 81.1% were owner-occupied and 18.9% were renter-occupied. The homeowner vacancy rate was 1.2% and the rental vacancy rate was 6.9%.

Racial and ethnic composition +Will County, Illinois – Racial and ethnic compositionRace / Ethnicity (NH = Non-Hispanic)Pop 1980Pop 1990Pop 2000Pop 2010 Pop 2020% 1980% 1990% 2000% 2010% 2020White alone (NH)275,048294,103388,523455,577418,41884.77%82.31%77.35%67.24%60.09%Black or African American alone (NH)31,22737,75251,98074,41979,2569.62%10.57%10.35%10.98%11.38%Native American or Alaska Native alone (NH)4846176728147110.15%0.17%0.13%0.12%0.10%Asian alone (NH)2,8164,60811,02130,45842,4160.87%1.29%2.19%4.50%6.09%Native Hawaiian or Pacific Islander alone (NH)x included in the Asian category in the 1980 Censusx included in the Asian category in the 1990 Census12010482xx0.02%0.02%0.01%Other race alone (NH)1,1072605367512,1050.34%0.07%0.11%0.11%0.30%Mixed race or Multiracial (NH)x not an option in the 1980 Censusx not an option in the 1990 Census5,6469,62022,516xx1.12%1.42%3.23%Hispanic or Latino (any race)13,77819,97343,768105,817130,8514.25%5.59%8.71%15.62%18.79%Total324,460357,313502,266677,560696,355 100.00%100.00%100.00%100.00%100.00%

Racial / Ethnic Profile of places in Will County, Illinois (2020 census) Racial / Ethnic Profile of places in Will County, Illinois (2020 Census)Following is a table of towns and census designated places in Will County, Illinois. Data for the United States (with and without Puerto Rico), the state of Illinois, and Will County itself have been included for comparison purposes. The majority racial/ethnic group is coded per the key below. Communities that extend into and adjacent county or counties are delineated with a followed by an accompanying explanatory note. The full population of each community has been tabulated including the population in adjacent counties. Majority minority with no dominant groupMajority WhiteMajority BlackMajority HispanicMajority Asian