Renewable energy in Iceland has supplied over 70% of Iceland's primary energy needs since 1999 - proportionally more than any other country - and 99.9% of Iceland's electricity is generated from hydroelectricity and geothermal power. In 1998 the Icelandic Parliament committed to convert the national vehicle and fishing fleets to hydrogen fuel produced from renewable energy by 2050. This would make Iceland the first completely energy-independent country in the world to use 100% renewable energy sources.

Iceland's location on the Mid-Atlantic Ridge makes it one of the most tectonically active places in the world, with over 200 volcanoes and over 20 high-temperature steam fields. Geothermal energy for heating was first used in 1907 when a farmer piped steam from a hot spring into his house. In 1930, the first pipeline was constructed in Reykjavík, heating two schools, 60 homes, and the main hospital. In 1943, the first geothermal district heating company started. Geothermal power now heats 89% of the nation's houses, provides around 19% of electricity generation and over 54% of primary energy. The first hydroelectric plant was built in 1904 and produced 9 kW of power. Hydropower now provides 81% of Iceland's electricity supply.

Imported oil provides most of Iceland's remaining energy. Replacing this with hydrogen was first suggested after the 1970s energy crisis, but the idea was not adopted until 1998. Iceland's small size makes it ideal for testing the viability of hydrogen as a fuel source for the future, while the plentiful renewable energy sources can be harnessed for its production. Iceland participates in international hydrogen fuel research and development programs, and many countries are following the nation's progress.

As a result of its transition to renewable energy, Iceland is ranked 53rd in the list of countries by carbon dioxide emissions per capita in 2003, emitting 62% less than the United States despite using more primary energy per capita.