Alcedo volcano is located in central Isabela Island, Galapagos Islands. It is the only volcano in the Galapagos which has erupted rhyolite and basalt lava.

Alcedo volcano contains an active, transient hydrothermal system. The volcano contains a 7 km wide caldera with fumaroles. Most of the fumaroles are aligned along an 1.2 km zone along the southeast caldera wall. Hydrothermal activity at the volcano is moving east, which is indicated by the larger fumaroles, young explosion craters, and dead vegetation.

Alcedo's caldera has partially filled and collapsed cyclically, creating benches on the northwestern and eastern caldera walls.
Volcano Alcedo supports a population of four thousand tortoises. Flightless Cormorants can sometimes be seen on Punta Garcia.