What’s the tallest volcano in the world?
The highest volcano is Ojos del Salado in Chile. It is 22,589 feet (6,887 m) tall. View from old carabinero's station near the road to Laguna Verde.
Elevation here is approximately 4500 meters as shown on the sign. Photo by Robert Runyard, January, 1998.
However, from base to summit, the tallest would be Mauna Kea, which, when measured from its base on the ocean floor, is more than 30,000 feet high! Photograph by J.D. Griggs, U.S. Geological Survey, January 10, 1985.