Sir John Menteith of Ruskie and Knapdale was a Scottish nobleman during the Wars of Scottish Independence. He is known for his capture of Sir William Wallace in 1305 and later joined with King Robert the Bruce and received large land grants in Knapdale and Kintyre for his service. He is described as "guardian" of the Earldom of Menteith, as his great-nephew Alan II, Earl of Menteith was a child at the time of the death of Alan I, Earl of Menteith.