• Companies based in Illinois by county‎ (34 C)
• Companies based in Illinois by populated place‎ (15 C)

-

• Defunct companies based in Illinois‎ (6 C, 87 P)

*

• Lists of companies based in Illinois‎ (4 P)

A

• Architecture firms based in Illinois‎ (2 C, 3 P)

B

• Book publishing companies based in Illinois‎ (41 P)

C

• Cooperatives based in Illinois‎ (1 C, 24 P)

F

• Financial services companies based in Illinois‎ (5 C, 8 P)
• Food and drink companies based in Illinois‎ (7 C, 14 P)

H

• Health care companies based in Illinois‎ (4 C, 24 P)

L

• Law firms based in Illinois‎ (1 C, 3 P)

M

• Manufacturing companies based in Illinois‎ (6 C, 85 P)
• Metal companies based in Illinois‎ (1 P)
• Motor vehicle assembly plants in Illinois‎ (3 P)
• Motor vehicle manufacturers based in Illinois‎ (1 C, 50 P)

P

• Privately held companies based in Illinois‎ (1 C, 79 P)

R

• Record labels based in Illinois‎ (33 P)
• Restaurants in Illinois‎ (11 C, 29 P)
• Retail companies based in Illinois‎ (1 C, 5 P)

S

• Software companies based in Illinois‎ (1 C, 40 P)

T

• Theatre companies in Illinois‎ (2 C, 10 P)
• Company towns in Illinois‎ (10 P)
• Transportation companies based in Illinois‎ (2 C, 12 P)

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• Template:Illinois Corporations
• List of companies in the Chicago metropolitan area
• List of Illinois companies

C

• Center for COVID Control

D

• Darvin Furniture & Mattress
• Disaster Kleenup International

G

• GP Transco

H

• H. Kramer and Company
• Hearthside Food Solutions

I

• Instant Brands

M

• MAT Holdings
• Montgomery Ward

N

• News Media Corporation

O

• Other World Computing

P

• Pharmazz

R

• R. P. Home & Harvest
• Ravn Aerospace
• Rock'n Vodka

S

• Sprout Social
• Stover Bicycle Manufacturing Company
• Stover Engine Works
• Suburban Bancorp