In Norse mythology, Gríðr (Old Norse "greed" or "greed, vehemence, violence, impetuosity") is a female jötunn who, aware of Loki's plans to have Thor killed at the hands of the giant Geirröd, helped Thor by supplying him with a number of magical gifts which included a pair of iron gloves, and a staff known as Gríðarvölr. These items saved Thor's life. She is also the mother of the god Víðarr by Odin.
Gríðr is referenced in the poem Þórsdrápa and in Snorri Sturluson's Skáldskaparmál. She or a someone of the same name appears as a witch in Illuga saga Gríðarfóstra.
Saxo Grammaticus refers to her as Grytha, the wife of the legendary king Dan I of Denmark, "a matron most highly revered among the Teutons".