In Norse mythology, Vídar is a god associated with vengeance and is the son of Odin and the giantess Gríd. His major deed in the mythology is to avenge his father's death at Ragnarok and is one of the few gods destined to survive that final conflict.
According to Gylfaginning, Vidar is called the silent god who wears a thick shoe, is almost equal in strength to Thor, and can always be counted on to help the Aesir in their struggles. During Ragnarök, when the wolf Fenrir devours Odin, Vidar will avenge him by stepping down with one foot on the lower jaw of the monster, grabbing his upper jaw in one hand and tearing his mouth apart, killing him. Vidar's "thick shoe" consists of all the leather waste pieces that people have cut from their own shoes at the toe and heel, collected by the god throughout all time. Therefore, anyone who is concerned enough to give assistance to the gods must throw these pieces away. Following Ragnarök and the rebirth of the world, Vidar along with his brother Váli will have survived both the deluge of the sea and the fiery conflagration unleashed by Surtr, completely unharmed, and shall thereafter dwell on the field of Idavoll, "where the city of Asgard had previously been".
According to Skáldskaparmál, when Aegir was a guest in Asgard, Vidar was one of the twelve presiding male gods seated among those hosting the banquet. Later in the book, various kennings are given for Vidar, including again the silent god, possessor of the iron shoe, enemy and slayer of Fenrisulf, the avenging god, brother of the Aesir, son of Odin and dweller of his father's homestead. In the tale of Thor's visit to the hall of the giant Geirröd, we are told that Gríd is the mother of "Vidar the Silent", and at a certain point in the dialogue between Bragi and Aegir, Snorri himself begins speaking of the myths in euhemeristic terms and states that the historical equivalent of Vidar was Aeneas who survived the Trojan War (Snorri's basis for Ragnarök) and went on to achieve great deeds.
According to Völuspá, Vidar slays Fenrir not by tearing his jaws apart but by thrusting his sword into the wolf's heart, although this does not prevent Snorri from quoting the passage after giving his own version in Gylfaginning.
According to Vafthrúdnismál, Vidar and Váli both "shall live in the temples of the gods when Surtr's fire is slaked". Also, "the wolf will swallow the Father of Men. Vidar will avenge this. The cold jaws of the beast he will sunder in battle". These passages, along with others from the same poem, are likewise quoted or expanded upon by Snorri in Gylfaginning.
According to Grímnismál, during Odin's visions of the various dwelling places of the gods he describes that of Vidar in stanza 17:
- "Brushwood grows and high grass
- widely in Vidar's land
- and there the son proclaims on horseback
- his eagerness to avenge his father"
According to Lokasenna, Loki rebukes the gods at the start of the poem for not properly welcoming him to the feast at Aegir's hall, so Odin finally relents to the rules of hospitality, urging Vidar to stand and pour a drink for the quarrelsome guest.
John Lindow, in his book Norse Mythology (2001), speculates that Vidar's silence may derive from a ritual silence or other abstentions which often accompany acts of vengeance, as for example in Völuspá and Baldrs draumar when Váli, conceived for the sole purpose of avenging Baldr's death, abstains from washing his hands and combing his hair "until he brought Baldr's adversary to the funeral pyre".