Established in 1989, Ontario Teachers' Pension Plan (Ontario Teachers') is Canada's largest single-profession pension plan, investing the pension fund's assets and administering the pensions of Ontario's 331,000 active and retired teachers as of 2023. The organization's headquarters are in Toronto, Ontario, with offices in London and Hong Kong, and it employs over 1,200 employees globally.

Ontario Teachers' is an independent organization that pays defined benefit pensions and invests the pension fund's assets. As of 2022, the plan's net assets stood at $221.2 billion, making it one of Canada's largest institutional investors.