William d'Aubigny, 3rd Earl of Arundel, also called William de Albini IV,[1] (before 1180 – 1 February 1221) was an English nobleman, a favourite of King John, and a participant in the Fifth Crusade.

He returned to the allegiance of the King Henry III after the Royalist victory at Lincoln, on 14 July 1217.

He died on his journey home, in Caneill, Italy, near Rome, on 1 February 1221.

The fourth earl died childless and in 1224 the title passed to his brother, Hugh.

At some time between 1196 and 1200 William married Mabel of Chester (born c. 1173), the second daughter of Hugh de Kevelioc, 5th Earl of Chester (aliter "Hugh le Meschin"), by his wife Bertrade de Montfort, a daughter of Simon, Count of Evreux in Normandy.