Brigadier William Mackintosh, Laird of Borlum (1658–1743) usually known as Mackintosh of Borlum was a leader of the Jacobite rebellion of 1715 and a member of the Clan Mackintosh.
The leader of the rising, John Erskine, 23rd Earl of Mar, detached a small force of 2000 Highlanders led by Borlum from the main army. He moved into Fife and crossed the Firth of Forth in fishing boats. He briefly held Leith and came close to capturing Edinburgh. He linked up with some English and Lowland Jacobites in the Scottish Borders, then marched south as far as Preston where they were captured (see Battle of Preston (1715)). He was charged with treason, but escaped from Newgate Prison with seven others the night before his trial was due to start.
One historian, John Prebble, considers that he should really have led the rising instead of Mar.
He also fought for the Jacobites at the Battle of Glen Shiel in 1719.
He married Mary Reade, and they had two sons.
There is a bagpipe tune called "Mackintosh of Borlum's Salute".