Sybil was an Anglo-Norman noblewoman in 12th-century England. Her parentage is unclear, but her first marriage to Pain fitzJohn is well attested. Through her marriage, Sybil transferred lands in several shires to her husband, including lands around Ludlow Castle and the castle itself. After Pain's death in 1137, Sybil attempted to retain control of Ludlow and her lands but in 1139 King Stephen of England married her to Josce de Dinan, who died in 1166. Sybil had two daughters with Pain, and is probably the mother of Josce's two daughters also. Sybil's marriage to Josce, and his control of Ludlow in right of his wife forms the background to a medieval Welsh romance, Fouke le Fitz Waryn.