Aviation fuel is a specialized type of petroleum-based fuel used to power aircraft. It is generally of a higher quality than fuels used in less critical applications, such as heating or road transport, and often contains additives to reduce the risk of icing or explosion due to high temperatures, among other properties.

Most aviation fuels available for aircraft are kinds of petroleum spirit used in engines with spark plugs (i.e. piston and Wankel rotary engines), or fuel for jet turbine engines, which is also used in diesel aircraft engines. Alcohol, alcohol mixtures and other alternative fuels may be used experimentally, but alcohol is not permitted in any certified aviation fuel specification.

The Convention on International Civil Aviation (ICAO), which came into effect in 1947, exempted air fuels from tax. Australia and the USA oppose a worldwide levy on aviation fuel, but a number of other countries have expressed interest.

Fuels have to conform to a specification in order to be approved for use in type certificated aircraft. The American Society for Testing and Materials (ASTM) developed specifications for automobile gasoline as well as aviation gasoline. These specifications are ASTM D 910 and ASTM D 6227 for aviation gasoline and ASTM D 439 or ASTM D 4814 (latest revision) for automobile gasoline.