The Battle of Harlaw (Scottish Gaelic: Cath Gairbheach) was a Scottish clan battle fought on 24 July 1411 just north of Inverurie in Aberdeenshire. It was one of a series of battles fought during the Middle Ages between the barons of northeast Scotland against those from the west coast.

The battle was fought to resolve competing claims to the Earldom of Ross, a large region of northern Scotland. Robert Stewart, Duke of Albany, Regent of Scotland, had taken control of the earldom as guardian of his niece Euphemia Leslie. This claim was contested by Donald, Lord of the Isles, who had married Euphemia's aunt Mariota. Donald invaded Ross with the intention of seizing the earldom by force.

First he defeated a large force of Mackays at the Battle of Dingwall. He captured Dingwall Castle and then advanced on Aberdeen with 10,000 clansmen. Near Inverurie he was met by 1,000–2,000 of the local gentry, many in armour, hastily assembled by the Earl of Mar. After a day of fierce fighting there was no clear victor; Donald had lost 900 men before retreating to the Western Isles, and Mar had lost 600. The latter could claim a strategic victory in that Aberdeen was saved, and within a year Albany had recaptured Ross and forced Donald to surrender. However Mariota was later awarded the earldom of Ross in 1424 and the Lordship of the Isles would keep the title for much of the 15th century.

The ferocity of the battle gave it the nickname "Red Harlaw". It is commemorated by a 40-foot (12 m) high memorial on the battlefield near Inverurie, supposedly by the church at Chapel of Garioch, and by ballads and music.