William de Leybourne

Admiral Sir William de Leybourne
Born1242
Leybourne Castle, Leybourne, Kent, England
Died18 March 1310
Preston, near Wingham, Kent.
Allegiance England
Branch Royal Navy
Years of service1265–1306
RankAdmiral
CommandsAdmiral of the English Seas
Admiral of the South
Admiral of the West
Admiral of the Irish Sea
Battles / warsBattle off Bruges
Siege of Bayonne
Siege of Caerlaverock
Siege of Winchelsea

Admiral Sir William de Leybourne (French: Guillaume de Leybourne; Latin: Willelmus de Leyburnia or Leyburna; c. 1242–1310) was an English knight and military commander, sometimes reckoned the first admiral of the English navy.