Walter Stewart, Earl of Atholl, Strathearn and Caithness (c. 1360 – 26 March 1437) was a Scottish nobleman, the son of Robert II of Scotland. Stewart advocated for the ransom and return to Scotland of the future king in exile, James I, in 1424. In 1425 he served as a member of the jury of 21 which tried and executed his nephew Murdoch Stewart, 2nd Duke of Albany. Eventually, however, Atholl turned against the King and conspired in his assassination in 1437. He was tried for murder and was executed after three days of torture.