Hafragilsfoss is an 85-meter wide and 27-meter high waterfall on the glacial river Jökulsá á Fjöllum. It is the least known and least visited of the trio Selfoss – Dettifoss – Hafragilsfoss.

It is located about 2 kilometers downstream from Dettifoss. You can easily reach the beautiful (eastern) viewpoint of the waterfall by car. The western viewpoint is a bit difficult to reach.