Thomas de Thelwall (died 1382) was an English judge and Crown official who spent part of his career in Ireland, where he held office as Master of the Rolls in Ireland and clerk to the Privy Council of Ireland. He was Chancellor of the Duchy of Lancaster 1377-78.
Little is known of his early life; his surname suggests that he was a native of Thelwall, Cheshire. He is first heard of as a clerk in the Royal Chancery about 1360. He was presented to the living of Polebrook in Northamptonshire in 1361.
In 1369 he accompanied William de Windsor, the new Lord Lieutenant, to Ireland; he became Master of the Rolls in 1372 and a prebendary of St Patrick's Cathedral, Dublin. Otway-Ruthven describes him in 1374 as Clerk to the Irish Privy Council, one of the first men to have held this office.
He returned to England about 1375 and was briefly Chancellor of the Duchy of Lancaster. He is thought to have died in 1382.