What is the name of the battlefield of Ragnarok?

The battlefield of Ragnarök is Vígríðr, also anglicized as Vigrid.

Vígríðr is described in Norse myth as a vast plain where the gods and the forces opposing them meet for the final battle. The name is commonly interpreted as meaning “battle-surge” or “the place where battle surges.” The Poetic Edda names the field in Vafþrúðnismál, while the Prose Edda gives a fuller account of the battle’s participants.

The Prose Edda says the field stretches for one hundred leagues in every direction. Odin and the gods travel there in battle gear, while Surtr and the forces of Muspell, Fenrir, Jörmungandr, Loki, and the frost jötnar assemble on the opposing side. Heimdallr blows Gjallarhorn before the gods gather and advance.

Vígríðr is not the same as Midgard, the human world; Jotunheim, the land associated with the jötnar; or Asgard, the gods’ stronghold. Some traditions also associate the final battle with the name Óskópnir, but Vígríðr is the standard canonical answer to this question.