No.Business NameNumber of EmployeesLine of Business
1 Aon Hewitt 3,864 Global human resources; outsourcing and consulting
2 Zebra Technologies 1,743 Marking, tracking and computer printing technologies
3 CDW 1,250 Technology products and services
4 School District 125 1,108 Public education
5 HydraForce 670 Hydraulic cartridge valves and control systems
6 Quill 425 Office products and supplies
7 Sedgebrook 376 Senior living and care retirement community
8 Lincolnshire-Prairie View School District 103  373 Public education
9 Marriott Resort 312 Resort/entertainment
10 Sysmex 281 Medical equipment and devices