Gilbert de Clare, 1st Earl of Hertford

Gilbert de Clare, 1st Earl of Hertford ( † around 1151 ) was an Anglo-Norman nobleman of the family of de Clare.

He was the eldest son of Richard de Clare FitzGilbert and his wife Adeliza, daughter of Ranulph le Meschin, 1st Earl of Chester. After the assassination of his father in 1136 he inherited his possessions in southern England Clare and Tonbridge, while the Welsh possessions were lost by the Welsh victory in the Battle of Crug Mawr. He was created Earl of Hertford by King Stephen to 1138. In the succession dispute between Stephen and Matilda his rival he stood first on the side of the king and fought in the battles of Lincoln and Winchester. 1146 he presented himself to the king as a hostage for his uncle Ranulph de Gernon, 2nd Earl of Chester. As Ranulph but again switched sides, forced him to the king, to give him his castles. When Gilbert was subsequently released, he was also positive on the side of the opponent Stephen.

He died without male issue, his lands fell to his younger brother Roger. His widow Lucy 's second marriage was Baldwin de Redvers, 1st Earl of Devon.