John Prophet (1356–1416) was an English medieval Secretary to King Henry IV, Keeper of the Privy Seal and, Dean of Hereford and York. A distinguished and capable administrator he remained loyal to all kings through a mix of shrewdness, and cunning. Guilty of simony and pluralism, Prophet was no Lollard, but successfully made the transition from Richard II's extravagant court at Westminster to an indispensable servant of the Lancastrians.

The Dean of York is the member of the clergy who is responsible for the running of the York Minster cathedral. As well as being the head of the cathedral church of the diocese and the metropolitical church of the province, the Dean of York holds preeminence as the Province of York vicar.