William Douglas, 2nd Earl of Angus ( 1398 – 1437) was a Scottish nobleman and soldier. The son of George Douglas, 1st Earl of Angus and Princess Mary of Scotland, he was a grandson of King Robert III. The story of Angus' life is interwoven with that of his uncle and King, James I of Scotland. Angus was born about 1398 at Tantallon Castle in East Lothian. He inherited the Earldom of Angus in 1402, following his father's death of the plague whilst in English captivity, following the Battle of Homildon Hill.