Gilbert fitz Richard de Clare Earl Of Hertford
- Born: Abt 1065, Clare, Suffolk, England
- Marriage: Adeliza de Clermont before 1076 in England
- Died: Between 1114 and 1117, England
Gilbert De Clare of Tonebridge, son of Richard and Rohese, 2nd Earl of Clare, was born before 1066. He resided at Tonebruge and inherited all of his father's lands in England. He joined in the rebellion of Robert de Mowbray, Earl of Northumberland, against the king, but observing the William Rufus upon the point of falling into an ambuscade, he relented, besought pardon, and saved his royal master. We find him subsequently, however, again in rebellion, in the same reign, and fortifying and losing his castle at Tunbridge.
He married in 1113, Adeliza Clermont, daughter of Hugh de Clermont, 2nd Count of Clermont, and his wife, Marguerita, daughter of Hildwin IV, Count of Montidier and Lord of Rouci and Ramere, and his wife, Adela, Countess of Rouci, great granddaughter of Hugh Capet and his wife, Adela.
Gilbert married Adeliza de Clermont, daughter of Hugh Count Of Clermont (Creil, Mouchy) and Margaret (Marguerite) de Montdidier Countess Of Clermont, before 1076 in England. (Adeliza de Clermont was born about 1058 in Northamptonshire, England and died in England.)