Rivière du Loup (rēvyĕrˈ dü lō) [key], city (1991 pop. 14,017), E Que., Canada, on the south shore of the St. Lawrence River, NE of Quebec. It is a commercial and industrial center in a lumbering and agricultural region. There are saw and paper mills. It is also a resort and tourist center. Settled in 1833, it was originally called Fraserville.