Brunhild, also known as Brunhilda or Brynhild (Old Norse: Brynhildr [ˈbrynˌhildz̠], Middle High German: Brünhilt, Modern German: Brünhild or Brünhilde), is a female character from Germanic heroic legend. She may have her origins in the Visigothic princess and queen Brunhilda of Austrasia.

In the Norse tradition, Brunhild is a shieldmaiden or valkyrie, who appears as a main character in the Völsunga saga and some Eddic poems treating the same events. In the continental Germanic tradition, where she is a central character in the Nibelungenlied, she is a powerful Amazon-like queen. In both traditions, she is instrumental in bringing about the death of the hero Sigurd or Siegfried after he deceives her into marrying the Burgundian king Gunther or Gunnar. In both traditions, the immediate cause for her desire to have Siegfried murdered is a quarrel with the hero's wife, Gudrun or Kriemhild. In the Scandinavian tradition, but not in the continental tradition, Brunhild kills herself after Sigurd's death.

Richard Wagner made Brunhild (as Brünnhilde) an important character in his opera cycle Der Ring des Nibelungen. The majority of modern conceptions of the figure have been inspired or influenced by Wagner's depiction.

Brunhild has been called "the paramount figure of Germanic legend." The Nibelungenlied introduces her by saying:

Ez was ein küneginne gesezzen über sê.
ir gelîche enheine man wesse ninder mê.
diu was unmâzen schoene. vil michel was ir kraft.
si schôz mit snellen degenen umbe minne den schaft.

There was a queen who resided over the sea,
Whose like no one knew of anywhere.
She was exceedingly beautiful and great in physical strength.
She shot the shaft with bold knights – love was the prize.

The name Brunhild in its various forms is derived from the equivalents of Old High German brunia (armor) and hiltia (conflict). The name is first attested in the sixth century, for the historical Brunhilda of Austrasia, as Brunichildis.

In the context of the heroic tradition, the first element of her name may be connected to Brunhild's role as a shieldmaiden. In the Eddic poem Helreið Brynhildar, the valkyrie Sigrdrífa from Sigrdrífumál is identified with Brunhild. This name consists of the elements sigr and drífa and can be translated as "driver to victory". It could simply be a synonym for valkyrie.