Ragnvald Eysteinsson, The Wise (830-890) (Old Norse: Rögnvaldr Mærajarl), Earl of Sunnmøre, Nordmøre and Romsdal, was born in Maer Nord-Trøndelag, Norway and died at the Orkney Islands.

He was son of Eystein Glumra the Noisy, Earl of Oppland.

His second wife was Ragnhild Ragnhild Hrolfsdottir (Raghldr (Hldr) Hrolfsdóttir) daughter of Hrolfr Nefjaa. Ragnvald was the father of Hrolf Ganger, the founder of Normandy. He was also the father of Turf-Einar, the ancestor of the jarls of Orkney.

He was the direct ancestor to William I of England, Edward III of England, James I of England, and, therefore, Elizabeth II of the United Kingdom of Great Britain and Northern Ireland. He is therefore the ancestor of most of the royal families of Europe.