Will County, Illinois

Will County is a county in Illinois, United States, about 35 miles southwest of Chicago. It had a
population of 696,355 at the 2020 census, an estimated 712,253 by 2025, and covers 849 square
miles (2,199 km2) centred near 41°27′N 87°59′W.

Joliet is the county seat and its largest city; its postal code is 60435. The county holds 5
cities, 20 incorporated villages and 24 census-designated places and unincorporated communities
across 24 townships, and it runs on Central Time. Its FIPS code is 17197.

Towns & Villages in Will County

Will County has 49 named places on record: 25 incorporated cities and villages, plus 24
census-designated places (CDPs) and unincorporated communities with no municipal government of
their own. CDP stands for census designated place; Unincorp. covers crossroads and rural
settlements with no formal boundary. This is one of Illinois’ largest counties by population, so
the table below is split in two — every incorporated place first, then the CDPs and
unincorporated communities that fill in the rural and suburban fringe.

A second group of 24 places carries no incorporated government of its own — census
designated places (CDPs) the Census Bureau tracks for statistical purposes, and a couple of
long-standing unincorporated crossroads communities. Population and ZIP data are not published
separately for most of these; residents use the nearest incorporated town’s postal code.

Several places on this list are only partly inside Will County. Bolingbrook and Plainfield each
extend a short distance into DuPage and Kendall counties, but the great majority of both villages,
and their populations above, are Will County residents. Frankfort, Homer Glen, Steger and
University Park all carry a smaller slice into Cook County. Several much larger municipalities
— Aurora, Naperville, Oswego, Lemont, Orland Park, Tinley Park and Woodridge — hold only a
narrow annexed strip inside Will’s borders, with the overwhelming share of each city’s population
in a neighboring county, so they are not listed above. The same applies in reverse to Coal City,
Diamond and Minooka, three villages centred in Grundy and Kendall counties with a small edge
reaching into western Will. Will Township, one of the county’s 24 civil townships, shares its
name with the county itself but is a separate, much smaller unit covering rural land near
Rockdale and Channahon.

Townships

Illinois divides its counties into civil townships that handle roads, assessments and general
assistance. Will County has 24, sorted here alphabetically since 2020 census figures are not
published at the township level for most of them; land area is a stable measure that is.

ZIP Codes

• 60431, 60432, 60433, 60435, 60436 — Joliet (60434 is a Joliet PO box ZIP)
• 60440, 60490 — Bolingbrook
• 60544, 60585, 60586 — Plainfield
• 60446 — Romeoville
• 60451 — New Lenox
• 60441 — Lockport
• 60491 — Homer Glen
• 60403 — Crest Hill
• 60423 — Frankfort
• 60448 — Mokena
• 60404 — Shorewood
• 60410 — Channahon
• 60442 — Manhattan
• 60417 — Crete
• 60484 — University Park
• 60481 — Wilmington
• 60449 — Monee
• 60401 — Beecher
• 60468 — Peotone
• 60408 — Braidwood
• 60421 — Elwood

Steger, Rockdale, Godley and Symerton have no ZIP code of their own on the county’s current
list; mail in these four is delivered under a neighboring town’s code — Steger’s falls under a
Cook County ZIP shared with its Cook County half, and Rockdale, Godley and Symerton use Joliet,
Braidwood and Wilmington codes respectively.

Geography

Will County sits in the flat till plains of northeastern Illinois, land shaped by glaciers that
retreated roughly 14,000 years ago. Of its 849 square miles, 837 are land and 12 are water, about
1.5 percent, mostly the Des Plaines and Kankakee rivers and their backwaters rather than any
single large natural lake. The Des Plaines River crosses the county’s northwest corner through
Channahon and Joliet, joining the Kankakee River near Channahon to form the Illinois River —
the confluence sits inside what is now Illinois & Michigan Canal State Trail land. The county
is largely prairie farmland in its southern and western halves, giving way to denser Chicago
suburbs in the north around Bolingbrook, Plainfield and Romeoville.

Kane County lies to the northwest, DuPage County to the north, Cook County to the northeast,
Lake County, Indiana, to the east, Kankakee County to the south, Grundy County to the southwest,
and Kendall County to the west. Kane County,
DuPage County,
Cook County,
Lake County, Indiana,
Kankakee County and
Grundy County all border Will directly;
Kendall County also borders it to the west.

Demographics

Will County had a population of 696,355 at the 2020 census, and the latest estimate puts the
county near 712,253 residents by 2025. Joliet and Bolingbrook are by far the two largest
communities, together holding roughly a third of the county’s population. Median household income
runs about $109,984, well above Illinois’ statewide figure of about $80,306. Population density
works out to roughly 832 people per square mile of land, reflecting the county’s position as one
of the five “collar counties” ringing the Chicago-Naperville-Elgin metropolitan area, denser in
its northern townships and largely rural in the south.

Economy & Local Life

Health care and social assistance employs the most workers in the county, about 46,157 people,
followed by retail trade at 42,689 and manufacturing at 39,163. Logistics and warehousing anchor
much of that employment: the CenterPoint Intermodal Center, spanning Joliet and Elwood, is one of
the largest inland ports in North America, built around Union Pacific and BNSF Railway rail yards
that move containers between West Coast ports and the Midwest. Amazon operates several large
fulfillment centers across the county. The ExxonMobil Joliet Refinery, built in 1972 in Channahon
Township, is a major regional employer and one of the points where Canadian and Gulf Coast
pipelines converge. In Joliet itself, the Old Joliet Prison — the state’s largest prison when
it was completed in 1858, closed in 2002 and used as a filming location for The Blues Brothers in
1980 — reopened for public tours in 2018 and now draws visitors to the city’s downtown historic
district.

History

The Illinois General Assembly formed Will County on 12 January 1836, carving it out of Cook and
Iroquois counties. It was named for Conrad Will, a physician, salt manufacturer and delegate to
Illinois’ 1818 constitutional convention. The county seat city, Joliet, takes its name from a
different person entirely — French-Canadian explorer Louis Jolliet, who passed through the
area with Jacques Marquette in 1673 — a naming coincidence that confuses the two men in local
lore. Joliet was platted in 1834 and grew around limestone quarrying; the pale local stone, known
as Joliet or Athens marble, built much of 19th-century Chicago after the 1871 fire. In 1852, Will
County lost territory north of the Kankakee River when neighboring Kankakee County was organized
out of it and Iroquois County.

Getting There

Interstates 55, 57, 80 and 355 all cross Will County, meeting near Joliet in one of the busiest
interstate junctions in the Midwest. US Routes 6, 30, 45 and 52 also run through the county, along
with Illinois Routes 1, 7, 43, 50, 53, 59, 102, 113, 126, 129, 171 and 394.

• Chicago — about 35 miles northeast
• Naperville — about 15 miles north
• Aurora — about 20 miles northwest
• Kankakee — about 20 miles south

Chicago Midway International Airport, roughly 25 miles northeast of Joliet, is the nearest
major commercial airport; Chicago O’Hare International is about 40 miles north. Joliet Regional
Airport, on the city’s south side, handles general aviation. Amtrak’s Texas Eagle and City of
New Orleans trains, along with Metra’s Rock Island and Heritage Corridor commuter lines, all call
at Joliet Union Station.

Frequently Asked Questions

Where is Will County located?
It sits in northeastern Illinois, about 35 miles southwest of Chicago, bordered by Kane, DuPage,
Cook, Lake (Indiana), Kankakee, Grundy and Kendall counties.

What is the population of Will County?
696,355 at the 2020 census, with a 2025 estimate near 712,253.

How big is Will County?
849 square miles (2,199 km2), of which 837 square miles are land.

What is the county seat of Will County?
Joliet, platted in 1834, is the county seat and largest city.

How many towns and villages are in Will County?
25 incorporated cities and villages, led by Joliet, Bolingbrook and Plainfield, plus 24 census
designated places and unincorporated communities.

What ZIP codes does Will County use?
The 60401–60491 range covers most of the county, including 60435 for Joliet, 60440 for
Bolingbrook and 60586 for Plainfield; Steger, Rockdale, Godley and Symerton use a neighboring
town’s code.

What is Will County known for?
The CenterPoint Intermodal Center, one of North America’s largest inland ports, and the Old
Joliet Prison, a 19th-century state penitentiary featured in The Blues Brothers.

More counties in this state: Towns and villages in Illinois.