The 1970s energy crisis was a period in which the major industrial countries of the world, particularly the United States, faced substantial shortages, both perceived and real, of petroleum. The two worst crises of this period were the 1973 oil crisis, caused by the Arab Oil Embargo of OAPEC, and the 1979 energy crisis, caused by the Iranian Revolution.

The crisis period, however, began to unfold as a result of events at the end of the 1960s. It was during this time that petroleum production in the United States and some other parts of the world peaked. Subsequently during the 1970s world oil production per capita peaked.

The major industrial centers of the world were forced to contend with escalating issues related to petroleum supply. The fact that Western countries had to deal with potentially unfriendly sources in the Middle East and other parts of the world to maintain supply made the situation especially complex.

The crisis led to stagnant economic growth in many countries as oil prices climbed. Though there were genuine issues with supply, part of the run-up in prices resulted from the perception of a crisis. The combination of stagnant growth and price inflation during this era led to the coinage of the term stagflation.

An energy crisis is any great bottleneck (or price rise) in the supply of energy resources to an economy. In popular literature though, it often refers to one of the energy sources used at a certain time and place, particularly those that supply national electricity grids or serve as fuel for vehicles. There has been an enormous increase in the global demand for energy in recent years as a result of industrial development and population growth. Supply of energy is, therefore, far less than the actual demand.

Market failure is possible when monopoly manipulation of markets occurs. A crisis can develop due to industrial actions like union organized strikes and government embargoes. The cause may be over-consumption, aging infrastructure, choke point disruption or bottlenecks at oil refineries and port facilities that restrict fuel supply. An emergency may emerge during unusually cold winters due to increased consumption of energy.

Large fluctuations and manipulations in future derivatives can have a substantial impact on price. Large investment banks control 80% of oil derivatives as of May 2012, compared to 30% only a decade ago. Kuwaiti Oil Minister Minister Hani Hussein stated that "Under the supply and demand theory, oil prices today are not justified," in an interview with Upstream.