Thomas Stewart, 2nd Earl of Angus was born before 1331. He was the son of Sir John Stewart, 1st Earl of Angus and Margaret Abernethy.1 He married Margaret St. Clair, daughter of Sir William St. Clair and Isabel, on 3 June 1353, by Papal dispensation.1 He died in 1361 in Dunbarton Castle, from the plague while imprisoned for alleged complicity in the murder of King David II's mistress, Catherine Mortimer.

Thomas Stewart, 2nd Earl of Angus succeeded to the title of 2nd Earl of Angus [S., 1329] on 9 December 1331.1 He fought in the taking of Berwick in May 1355, where he commanded.1 He was one of the eight lords, of whom three were to place themselves in the hands of the English as security for the release of King David II.1 He held the office of Great Chamberlain [Scotland] from 1357 to 1358.1 On 18 August 1359 he had a safe conduct for four ships of Flanders, but he broke his engagement.1 In March 1359/60 he was charged to retrun to England to fulfill his obligations as hostage.