Gabriel of Melitene (died 1102/3) was the ruler of Melitene (modern Malatya). Along with Thoros of Edessa, Gabriel was a former officer of Philaretos Brachamios. Philaretos had installed Gabriel as the ruler of Melitene. Following the death of Philaretos in 1086 Melitene became completely independent of Byzantine control with the aid of the Danishmends. Eventually the Danishmends began harassing Melitene. Gabriel appealed to Bohemund I of Antioch for assistance.
In 1100 Bohemund came to Gabriel's aid along with his cousin Richard of Salerno and the Armenian Bishops of Marash and Antioch, but they were both captured and the Bishops slain by Malik Ghazi Gumushtekin, the Danishmend Emir of Sebastea, in the Battle of Melitene. Malik was now constantly raiding Gabriel's territories. Fearing an imminent attack on the city itself, Gabriel asked for help from Baldwin of Boulogne who had recently become King of Jerusalem, despite concerns that Baldwin might take over Melitene, as he did Edessa. Baldwin relieved the siege of Melitene and rescued Bohemund after which Gabriel recognized him as overlord of the city.
Some sources state that Gabriel's wife was a daughter of Constantine I, Prince of Armenia; however, the dates simply do not allow for it. The confusion appears to stem from identifying Thoros I, son of Constantine with Thoros of Edessa, the latter of whom Gabriel is attested as being the father-in-law. Gabriel must have had some connection to the Greek culture, either via his mother or wife and, if that connection was to the family of Constantine I, it was most likely further back. His wife may have been a daughter of Constantine's father Roupen, for example; or she may have been a daughter of Philaretos, the general under whom Gabriel served, but this is only speculation. In any case, he was presumably known by his contemporaries and subjects to be descended from a prominent family that was acceptable to both the Greeks and to the Armenians, which could suggest a mixed heritage. Gabriel was disliked by a number of his subjects for his Orthodox faith