Autarky is the characteristic of self-sufficiency, usually applied to societies, communities, states, and their economic systems.

Autarky as an ideology or economic approach has been attempted by a range of political ideologies and movements, especially left-wing ideologies like African socialism, mutualism, war communism, communalism, swadeshi, syndicalism (especially anarcho-syndicalism), and left-wing populism, generally in an effort to build alternative economic structures or to control resources against structures a particular movement views as hostile. Conservative, centrist and nationalist movements have also adopted autarky in an attempt to preserve part of an existing social order or to develop a particular industry.

Proponents of autarky have argued for national self-sufficiency to reduce foreign economic, political and cultural influences, as well as to promote international peace. Economists are generally supportive of free trade. There is a broad consensus among economists that protectionism has a negative effect on economic growth and economic welfare while free trade and the reduction of trade barriers has a positive effect on economic growth and economic stability.

Autarky may be a policy of a state or some other type of entity when it seeks to be self-sufficient as a whole, but it also can be limited to a narrow field such as possession of a key raw material. Some countries have a policy of autarky with respect to foodstuffs and water for national-security reasons. Autarky can result from economic isolation or from external circumstances in which a state or other entity reverts to localized production when it lacks currency or excess production to trade with the outside world.

An autarkic economy that also will not or cannot conduct outside trade is known as a closed economy.