Turbessel (, or ) is a fortress in south-eastern Turkey.
It was a part of the Byzantine Empire but came under control of local Armenian lords in the late 11th century. As a part of the County of Edessa, it was one of the main strongholds of the Frankish counts. After the fall of Edessa to Zengi, it became the principal city of what remained of the County until it was eventually sold to the Emperor Manuel I Comnenus in 1150. It fell to Nur ed-Din's Muslims within the year.