Brynhildr may refer to:
- The Japanese name of the weapon Brunhilde from Final Fantasy X.
- The Eidolon from Final Fantasy XIII.
- The weapon from Final Fantasy Type-0.
- The summon from Final Fantasy Legends II.
Brynhildr is a Shieldmaiden and a Valkyrie in Norse mythology. In the Völsunga saga, she was sent by Odin to decide a fight between two kings, but was punished by the god after helping his least-favored one then banished her to the top of mount Hindarfjall in the Alps. She must sleep within a ring of fire until any man rescues and marries her. Sigurd entered the castle and awoke Brynhildr by removing her helmet and cutting off her chainmail armor.
The two fell in love and Sigurd proposed to her with the magic ring Andvaranaut. She appears as a main character in the Völsunga saga and some Eddic poems treating the same events. Under the name Brünnhilde, she appears in the Nibelungenlied and therefore also in Richard Wagner's opera cycle Der Ring des Nibelungen.