Celestica Inc. (TSX: CLS NYSE: CLS) is a multinational electronics manufacturing services (EMS) company headquartered in Toronto, Canada. Celestica’s global manufacturing network comprises more than 40 locations in 11 countries in the Americas, Europe and Asia, supplying a wide variety of leading OEMs (original equipment manufacturers). In addition to manufacturing, the company's global services include design and engineering, systems assembly, fulfillment and after-market services.

Celestica's Toronto headquarters were originally the location of IBM's Toronto sales and support offices, which also supported a small manufacturing unit which built metal boxes for their mainframe computers and associated support systems. Eugene Polistuk, a graduate of the University of Toronto in 1969, joined IBM and rose through the ranks before taking over the Toronto manufacturing division in 1986.

As the world turned from mainframes to microcomputers, Polistuk's operations were forced to reduce headcount in 1986 and 1988. In response, Polistuk started to diversify the plant's product lines, building circuit boards, memory products and power supplies that could be used in a wide variety of IBM products. The $300 million investment was successful, and by 1993 most IBM divisions were buying some of the systems produced in Toronto. The factory site expanded several times.