Sigurd II Haraldsson (or Sigurd Munn) (Old Norse: Sigurðr Haraldsson) was king of Norway from 1136 to 1155. He was son of Harald Gille, king of Norway and his mistress Tora Guttormsdotter (Þóra Guthormsdóttir). He served as co-ruler with his half-brothers, Inge Haraldsson and Eystein Haraldsson. His epithet Munn means "the Mouth" in Old Norse. He was killed in the power-struggle against his brother, Inge, in an early stage of the civil war era in Norway.