Thomas Langley (c.1363 – 20 November 1437) was an English prelate who held high ecclesiastical and political offices in the early to mid-1400s. He was Dean of York, Bishop of Durham, twice Lord Chancellor of England to three kings, and a Pseudocardinal. In turn Keeper of the King's signet and Keeper of the Privy Seal before becoming de facto England's first Foreign Secretary. He was the second longest serving Chancellor of the Middle Ages.