Wulfhere (d. 675) was a King of Mercia (658 - 675). He restored the power of Mercia after its disastrous defeat at the Battle of Winwaed.

He was a younger son of King Penda, and was kept in concealment for some time after his father's defeat and death in 655. In 658, however, the Mercians rebelled against the supremacy of Oswiu, king of Northumbria, and Wulfhere became their king.

Unlike his pagan father, Wulfhere was an enthusiastic Christian, and he took energetic measures to spread Christianity in Mercia. He was greatly helped in this by his bishop Jaruman, and afterwards by St. Chad. Outside Mercia, he did something to induce the East and the South Saxons to accept Christianity, and is said to have founded one or two monasteries.

Wulfhere gained Lindsey from Northumbria, and he led a successful campaign against Wessex in 661; according to the Anglo-Saxon Chronicle, he "raided as far as Ashdown " and the Isle of Wight, which he gave to Aethelwald of Sussex. He extended his borders in all directions, but at the end of his reign he suffered a series of setbacks. In 674, he attempted an invasion of Northumbria, but was badly defeated by its king, Ecgfrith. In 675, there was a battle between the Mercians and the West Saxons under Aescwine. Wulfhere died in the same year, although the cause is unknown.

Wulfhere's wife was Eormenhild, a daughter of Eorcenberht, king of Kent, and he was succeeded by his brother Æthelred. His only son Coenred became king in 704 in succession to Æthelred. His only daughter was St Werburga or Werburh, abbess of Ely.

See Bede, Historica ecclesiastica, ed. C. Plummer (Oxford, 1896); and JR Green, The Making of England (1897-1899).