The Earl or Mormaer of Ross was the ruler of the province of Ross in northern Scotland.
In the early Middle Ages, Ross was part of the vast earldom of Moray. It seems to have been made a separate earldom in the mid 12th century, when Malcolm MacHeth is found designated Earl of Ross. Malcolm had earlier been imprisoned at Roxburgh for rebelling against David I, but when Malcolm's brother-in-law Somerled invaded Scotland, David was forced to relent and grant the earldom unto Malcolm.
The title was later granted by William the Lion to Floris III of Holland in 1161 upon Floris's marriage to William's sister Ada of Huntingdon. However, Floris held the title only in a nominal sense, as he took no active part in the governance of Ross. The title seems not to have been passed on, for in 1291 Floris's descendant is found complaining that the earldom had been deprived from him.
The true founder was the famous Ferquhard, from the Irish Ó Beólláin (O'Beolain, Boland, Bolan) family. This Ferquhard was the son of the lay parson of the monastery of Applecross, and was hence known as MacIntagart, meaning "son of the priest". In 1215 the newly-crowned Alexander II was forced to suppress a rebellion in Moray and Ross. Ferquhard sided with the king, and captured the rebel leaders, before beheading them and presenting their heads to Alexander. For this he was knighted. He was created Earl of Ross in the 1220s, probably in 1226.