AbstractThis paper examines the diverse policy strategies that Canada’s largest oil-producing provinces have used to protect their oil sectors from constraints on emissions. Building from the literature on Canada’s staples/carbon trap, the paper explores how, over the most recent oil sector boom and bust period, Newfoundland and Labrador and Saskatchewan moved towards, but then avoided, constraining oil sector emissions. At the same time, Alberta implemented ostensibly pioneering climate policies but ultimately permitted significant emissions growth from the tar sands industry. The paper explains this variation by reviewing major institutional, interest group, and ideational conditions in each province, emphasizing the importance of non-oil interests contesting the oil sector and dominant notions of staples-led economic development.