Fredegund, or Frédégonde, (d. 597) was the Queen consort of Chilperic I, the Merovingian Frankish king of Soissons.

Originally a servant, Fredegund became Chilperic's mistress after he had murdered his wife and queen, Galswintha (c. 568). But Galswintha's sister, Brunhilda, in revenge against Chilperic, began a feud which lasted more than 40 years.

Fredegund is said to be responsible for the assassination of Sigebert I in 575 and made attempts on the lives of Guntram (her brother-in-law and the king of Burgundy), Childebert II (Sigebert's son), and Brunhilda.

After the mysterious assassination of Chilperic (584), Fredegund seized his riches and took refuge in the cathedral at Paris. Both she and her surviving son, Clotaire II, were protected by Guntram until he died in 592.

Said to be ruthlessly murderous and sadistically cruel, Fredegund perhaps has few rivals in monstrousness. [