Stewart of Balquhidder is a Perthshire branch of the Stewart clan and scions of the royal House of Stewart from an illegitimate branch. They are descended from Sir William Stewart of Baldorran (c.1440 – c.1500), who was the great grandson of Murdoch Stewart, Duke of Albany, executed by King James I of Scotland for treason in 1425. Murdoch Stewart was himself the grandson of King Robert II of Scotland, who founded the Stewart dynasty.