The Mormaer or Earl of Atholl was the title of the holder of a medieval comital lordship straddling the highland province of Atholl, now in northern Perthshire. Atholl is a special Mormaerdom, because a King of Atholl is reported from the Pictish period. The only other two Pictish kingdoms to be known from contemporary sources are Fortriu and Circinn. Indeed, the early 13th century document known to modern scholars as the de Situ Albanie repeats the claim that Atholl was an ancient Pictish kingdom. In the 11th century, the famous Crínán of Dunkeld may have performed the role of Mormaer.

Harald Maddadsson was Earl of Orkney and Mormaer of Caithness from 1139 until 1206. He was the son of Matad, Mormaer of Atholl, and Margaret, daughter of Earl Haakon Paulsson of Orkney. Of mixed Norse and Gaelic blood, and a descendant of Scots kings, he was a significant figure in northern Scotland, and played a prominent part in Scottish politics of the twelfth century. The Orkneyinga Saga names him one of the three most powerful Earls of Orkney along with Sigurd Eysteinsson and Thorfinn Sigurdsson.