Ófærufoss is a waterfall situated in the Eldgjá chasm in central Iceland. Until the early 1990s a natural bridge spanned the falls, but it collapsed from natural causes.

Situated between Landmannalaugar and Kirkjubæjarklaustur, Eldgjá is the largest volcanic canyon in the world, approx. 40 km long, 270 m deep and 600 m wide at its greatest.

The first documented eruption in 939 was the largest flood basalt in historic time. The areal extent of the lava is around 800 km2. An estimated 18 km3 of magma poured out of the earth. Evidence from tree rings from around the Northern Hemisphere indicated that the eruption in 939 caused the summer of 940 to be one of the coolest summers in 1500 years. Summer average temperatures in places as disparate as Central Europe, Scandinavia, Canada, Alaska, and Central Asia were 2°C lower than normal.