Earl of Airth was a title in the Peerage of Scotland, created on 21 January 1633 by Charles I, for William Graham, 7th Earl of Menteith. It became extinct on the death of his grandson in 1694.
Owing to the uncanonicity of the marriage of Robert II to Elizabeth Mure, and the 1373 Act which only sidestepped this question for heirs male of Robert II's sons, William Graham's ancestors potentially had a better claim to the Scottish throne than Mary, Queen of Scots. Graham thus had a potentially better claim to the throne than Mary's descendant, Charles I, as Graham's claim descends from Robert II's second - undoubted - marriage. Graham had successfully petitioned for the return of the title of Earl of Strathearn which the first Graham Earl of Mentieth had held. Before he was invested, however, Graham boasted that his blood was "bluer than the King's". He was dismissed from his positions and instead of receiving the Earldom of Strathearn, he was given the insultingly minor title of Earl of Airth.