William de Forz, 4th Earl of Albemarle

William de Forz, 4th Earl of Albemarle (died 1260) (Latinised as de Fortibus, sometimes spelt Deforce) played a conspicuous part in the reign of Henry III of England, notably in the Mad Parliament of 1258.

His first wife was Christina (died 1246), daughter and co-heiress of Alan, Lord of Galloway.

He got the title, but the court decided that the lands should be divided, but this wife died in 1239 without issue.

However, he and his wife quitclaimed the earldom to Henry III in 1241 in exchange for modest lands elsewhere.

Two years after the death of his first wife, he remarried in 1248 to Isabella de Redvers (1237–1293), daughter of Baldwin de Redvers, 6th Earl of Devon and Lord of the Isle of Wight.