No.Business NameNumber of EmployeesLine of Business
1 Aon Hewitt 3,877 Global human resources; outsourcing and consulting
2 Zebra Technologies 1,743 Marking, tracking and computer printing technologies
3 School District 125 1,132 Public education
4 CDW 1,100 Technology products and services
5 Walgreens 1,000 Pharmaceutical products
6 HydraForce 670 Hydraulic cartridge valves and control systems
7 W. W. Grainger 503 Industrial supplies, equipment, tools and materials
8 Quill 450 Office products and supplies
9 Lincolnshire-Prairie View School District 103  445 Public education
10 Sedgebrook 366 Senior living and care retirement community