Sweyn II Estridsson (Old Norse: Sveinn Ástríðarson, Danish: Svend Estridsen) was King of Denmark from 1047 until his death in 1074. He was the son of Ulf Jarl and Estrid Svendsdatter. He was married three times, and fathered 20 children or more out of wedlock, including the five future kings Harald III Hen, Canute IV the Saint, Oluf I Hunger, Eric I Evergood, and Niels.
He was courageous in battle, but did not have much success as a military commander. His skeleton reveals that he was a tall, powerfully built man who walked with a limp.