John Holland, 1st Duke of Exeter, 1st Earl of Huntingdon (c. 1352 – 16 January 1400), KG, of Dartington Hall in Devon, was a half-brother of King Richard II (1377–1399), to whom he remained strongly loyal. He is primarily remembered for being suspected of assisting in the downfall of King Richard's uncle Thomas of Woodstock, 1st Duke of Gloucester (1355–1397) (youngest son of King Edward III) and then for conspiring against King Richard's first cousin and eventual deposer, Henry Bolingbroke, later King Henry IV (1399–1413).