No.Business NameNumber of EmployeesLine of Business
1 Aon - Alight 3,510 Global human resources; outsourcing and consulting
2 CDW 1,152 Technology products and services
3 Zebra Technologies 1,100 Marking, tracking and computer printing technologies
4 HydraForce 696 Hydraulic cartridge valves and control systems
5 Adlai E. Stevenson High School District 125 658 Public education
6 Quill 450 Office products and supplies
7 Sedgebrook Senior Living 356 Senior living and care retirement community
8 Lincolnshire-Prairie View School District 103 337 Public education
9 Marriott Resort 330 Resort/entertainment
10 Sysmex 305 Medical equipment and devices