Temperature and pressure conditions required for the stability of natural gas hydrates are found in sediments of Canada's permafrost and offshore regions. Geophysical evidence suggests that a significant amount of methane is stored as gas hydrate in these regions. Gas hydrates may be an important contributor to future energy supplies and a source of atmospheric greenhouse gas. They may pose a hazard during exploration drilling or hydrocarbon production. Knowledge of their distribution is therefore required to evaluate their importance as an energy resource or drilling hazard. Stability conditions for the existence of gas hydrate in the Canadian permafrost and offshore regions have been analyzed. The distribution of gas hydrate, inferred from geophysical evidence, is described. Examples are presented to illustrate the role climatic and geological history, gas chemistry, and existing temperature and pressure conditions play in determining the stability and distribution of gas hydrate.