Sweyn II Estridsson (c. 1019 – 28 April 1074 or 1076) is King of Denmark from 1047 until his death in 1074.

He is the son of Ulf Jarl and Estrid Svendsdatter.

He is married three times, and fathers 20 children or more, including the five future kings Harald III Hen, Canute IV the Saint, Oluf I Hunger, Eric I Evergood and Niels out of wedlock.

He is courageous in battle, but does not have much success as a military commander.

His skeleton shows him to have been a tall, powerfully built man who walked with a limp.