Ragnvald Knaphövde was a King of Sweden whose reign is estimated to have occurred in the mid-1120s or c. 1130. His cognomen Knaphövde is explained as referring to a drinking vessel, the size of a man's head or meaning "round head" and referring to his being foolish. Ragnvald is mentioned in the regnal list of the Westrogothic law as the successor of King Inge the Younger.
His parentage is uncertain: King Inge the Elder of Sweden had a son named Ragnvald, and historian Sven Tunberg has suggested him as identical with Ragnvald Knaphövde. However, another tradition presents King Ragnvald as the son of an Olof Näskonung (Neskonungr meant "king of a ness" or "petty king", in Old Norse), and the regnal list of the Westrogothic law does not mention that Ragnvald had any connection with the old line of kings.
Ragnvald Knaphövde had been elected king by the Swedes in Uppland and then acknowledged by the East Gothlanders in Östergötland, but when he entered Västergötland, he did so without taking Geatish hostages. In Karleby, he was murdered by the Geats who instead had elected the Danish prince Magnus Nielsen who became King Magnus I of Sweden.