Erta Ale is a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia, the most active volcano in Ethiopia. It is in the Afar Depression, a badlandish desert area spanning the border with Eritrea, and the volcano itself is surrounded completely by an area below sea level, making it one of the lowest volcanoes in the world.

Erta Ale is 613 metres (2,011 ft) high, with one or sometimes two active lava lakes at the summit which occasionally overflow on the south side of the volcano. It is notable for being the longest-existing lava lake, present since the early years of the twentieth century (1906). Volcanoes with lava lakes are very rare: there are only five in the world.

Erta Ale means "smoking mountain" in the local Afar language and its southernmost pit is known locally as "the gateway to hell".