No.Business NameNumber of EmployeesLine of Business
1 Aon - Alight 3,750 Global human resources; outsourcing and consulting
2 Zebra Technologies 1,743 Marking, tracking and computer printing technologies
3 CDW 1,100 Technology products and services
4 Adlai E. Stevenson High School District 125 900 Public education
5 HydraForce 739 Hydraulic cartridge valves and control systems
6 Quill 450 Office products and supplies
7 Sedgebrook 366 Senior living and care retirement community
8 Marriott 335 Resort/entertainment
9 Lincolnshire-Prairie View School District 103  327 Public education
10 Sysmex 302 Medical equipment and devices