Herleva (c. 1003 – c. 1050) was an 11th-century Norman woman known for having been mother of William the Conqueror, born to an extramarital relationship with Robert I, Duke of Normandy, and also of William's prominent half-brothers Odo of Bayeux and Robert, Count of Mortain, born to Herleva's marriage to Herluin de Conteville.