Maccus of Orkneyar (855-879) was an Orcadian Viking leader during the late 9th century AD. He assumed command of the remnants of Jarl Sigurd Eysteinsson's army following the Battle of Balloch in 879, but, that winter, he and the remaining 100 Orcadians were annihilated by King Aed mac Cinaeda of Scotland's army.