In Norse mythology, Vidar (Víðar, Vidarr, Widar) is the Son of Odin and the giantess Grid (Jotun). He is the God of Silence, Stealth, and Revenge. In the reborn world that arises after Ragnarok, Vidar is preordained to rule in Odin's stead and to rebuild peace with the help of his brother Vali.

During Ragnarok, Odin is eaten alive by the wolf Fenris and Vidar will avenge his death by killing the beast. According to the Song of Vafthrudnismal (part of the Edda), Vidar killed Fenris by stepping on his lower jaw with his foot, on which he wore a shoe that consisted of strips of leather which men, followers of the Aesir, pare off at the toes and heels of their shoes to strengthen it. Having his foot placed, he will take the wolf's upper jaw and tear the beast apart. According to the Völuspá however, he used his sword (Stahl) to kill the wolf by driving it straight into its heart.

Vidar is being referred to as "the silent As" in the Skaldskaparmal (second part of the Younger Edda).