TORONTO—Low oil prices in western Canada are the most important new shock facing the Canadian economy and will be the subject of targeted conversations with the energy industry ahead of the Bank of Canada’s January interest-rate decision, Governor Stephen Poloz said Thursday.

Mr. Poloz said the central bank had expected to see some improvement in prices for heavy Canadian oil as U.S. refineries came back online, and the discount on Western Canadian Select has narrowed in line with those expectations. However, he said a backlog...