Sir Robert Crull (1349–1408) was the Treasurer of Ireland during the reigns of Richard II and Henry IV. Crull is an important figure in the history of English Ireland during the reign of Richard II (1382–1399) for two reasons: his involvement in the antagonism between the Geraldine and Butler families at its most notorious stage, and being at times a sacrificial lamb in Richard II's power struggle with the English Parliament over the stormy colonial politics that ensued.