Jon Haraldsson was a Norwegian noble who served as the Jarl of Orkney between 1206 and 1231. Jon Haraldsson and his brother David were the sons of Harald Maddadsson with his second wife Hvarflod, daughter of Earl Máel Coluim of Moray. Jon and David were joint Earls of Orkney after the death of their father in 1206. David Haraldsson died of sickness in 1214, leaving Jon Haraldsson to rule alone. William the Lion, king of Scotland, took Jon's daughter hostage in August 1214 as part of a peace agreement with the new sole Earl.