Illinois Business by the Numbers: 2026 Company Breakdown

Key findings

• Illinois ranks 9th nationally with 1,843,395 companies — 2.8% of all 64,799,929 U.S. companies in the directory.
• Chicago is the state’s largest business hub, with 470,991 companies — 25.6% of every company in Illinois.
• Business is concentrated in a few metros: Chicago, Naperville and Rockford together hold 28.5% of the state’s companies.
• Industrial & mechanical leads the state’s industries at 508,039 companies (27.6%), across 9 tracked sectors.

How Illinois ranks nationally

Illinois and its closest neighbours by total company count. Select a state to open its own study.

Top Illinois cities by number of companies

These 10 cities account for 35.4% of all companies in Illinois. Select any city to browse its full company list.

Browse all Illinois companies →

Illinois companies by industry

Every company is classified by its primary industry using NAICS/SIC codes. Select a sector to see those Illinois companies.

What the numbers show

Illinois’s 1,843,395 companies place it 9th nationally, 2.8% of the U.S. total. Activity clusters in its largest metros — Chicago, Naperville and Rockford alone account for 28.5% of the state’s companies — while industrial & mechanical is the dominant sector at 27.6%. For buyers and sellers, that means the deepest pools of suppliers and manufacturers sit in a handful of cities and one or two sectors; the charts above link straight into each so you can shortlist by capability and region.

Methodology

Figures reflect companies listed in Factur’s U.S. business directory as of 2026, classified by headquarters city and primary industry using NAICS/SIC codes. “Companies” includes manufacturers, suppliers, and B2B businesses of all sizes; counts are directory totals, not official census figures, and percentages are computed against the Illinois directory total. Data compiled by Factur, a sales and marketing firm for B2B manufacturers.