Hverfjall (Icelandic pronunciation: [ˈkʰvɛrˌfjatl̥] ⓘ; also known as Hverfell [ˈkʰvɛrˌfɛtl̥]) is a tephra cone or tuff ring volcano in northern Iceland, to the east of Mývatn.

It erupted in 2500 BP in the southern part of the Krafla fissure swarm.

A landslide apparently occurred in the south part of the crater during the eruption, which accounts for the disruption to the round shape of the mountain.

At the same time an eruption occurred in the slopes above the valley of Hlíðardalur [ˈl̥iːðarˌtaːlʏr̥].

[citation needed] The rim of the crater is only accessible by two paths, from the northwest and south.