The Mormaer or Earl of Atholl was the title of the holder of a medieval comital lordship straddling the highland province of Atholl (Ath Fodhla), now in northern Perthshire.

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.

Matad was perhaps the most famous of the Mormaers, fathering Harald Maddadsson, a notorious rebel of the Scottish King and perhaps the first Gael to rule Orkney as Earl of Orkney.

The line of Máel Muire and Crínán came to an end when Forbhlaith, the daughter of Mormaer Henry married David de Hastings.