Bergelmir (/bɛərˈɡɛlmɪər/ bair-GEL-meer; Old Norse: [ˈberˌɡelmez̠]) is a jötunn in Norse mythology.

The Old Norse name Bergelmir has been variously translated as 'bear-yeller', 'mountain-yeller', or 'bare-yeller'. According to linguist Jan de Vries, the name should be read as ber-gelmir ('who roars like a bear') rather than berg-gelmir ('who roars in the mountains').

In Vafþrúðnismál (The Lay of Vafþrúðnir), Bergelmir is portrayed as the son of Þrúðgelmir and the grandson of the first jötunn Aurgelmir (Ymir). When Odin asks Vafthrúdnir who is the oldest among the æsir and the jötnar, the wise jötunn responds that:

A great many years before the earth was formed,
Bergelmir was born;
Thrúdgelmir was the father of this one,
And Aurgelmir the grandfather.

— Vafthrúdnismál, 29, trans. J. Lindow, 2002.

In the same poem, Odin then asks Vafthrúdnir about the monstrous birth of the offspring of Aurgelmir, and Vafthrúdnir responds:

A great many years before the earth was formed,
Bergelmir was born;
What I first remember is when the wise giant
Was placed on a lúðr.

— Vafthrúdnismál, 35, trans. J. Lindow, 2002.