The Ontario Teachers' Pension Plan Board (OTPP), commonly referred to as Teachers', is an independent organization responsible for administering defined-benefit pensions for school teachers of the Canadian province of Ontario. The OTPP also invests the plan's pension fund, and is one of the world's largest institutional investors. The plan is a multi-employer pension plan, jointly sponsored by the Government of Ontario and the Ontario Teachers' Federation.

OTPP owns a substantial portfolio of infrastructure assets including minority stakes in Birmingham International Airport, Bristol International Airport, Copenhagen Airport and Brussels Airport; the High Speed 1 rail line linking London with the Channel Tunnel; and international water and power utilities.