John Stewart, 3rd Earl of Lennox was a prominent Scottish magnate.
He was the son of Matthew Stewart, 2nd Earl of Lennox, and Elizabeth Hamilton, daughter of James Hamilton, 1st Lord Hamilton and Mary Stewart, Princess of Scotland, daughter of King James II of Scotland.
The Earl of Lennox led an army to Linlithgow with the intention of liberating the young King James V from the pro-English Douglases. He was defeated by a smaller force led by the Earl of Arran at the Battle of Linlithgow Bridge. He survived the battle and was taken captive only to be subsequently murdered by James Hamilton of Finnart.