This publication provides a review of the developments in Ontario in relation to the national and international energy scene. Ontario is the largest energy consumer in Canada and is highly dependent on external energy sources. Several developments have significantly altered the Ontario energy scene. Oil and gas markets have become deregulated and market forces increasingly determine prices. A free trade agreement with the United States makes Ontario even more affected by international markets. Oil and gas prices have fallen from the high levels of the 1980s, but energy efficiency and conservation continue to be extremely important because they affect economic performance and the environment. In the next few years the greatest challenges will be to continue improving energy efficiency, to reduce the impact of energy on the environment, and to ensure the availability of sufficient energy supplies for future needs. This review contains statistics on energy in Ontario and explains them for the non-specialist. (7 tabs., figs.).