Peterborough, city (1991 pop. 68,371), SE Ont., Canada, NE of Toronto. It is at the falls of the Otonabee River, which connects, through the Trent Canal, with lakes Ontario and Huron. Settled early in the 19th cent. as a lumber town, it is a railroad and industrial center and is headquarters of the Canadian General Electric Company. Peterborough is also a resort for the Kawartha Lakes region. The lift-locks on the Trent-Severn waterway are the world's highest. Trent Univ. and a canoe museum are there. Archaeologically valuable Native American sites are nearby.