Rib-Hadda was king of Byblos during the mid fourteenth century BCE. He is the author of some sixty of the Amarna letters all to Akhenaten. His name is Akkadian in form and may invoke the Northwest Semitic god Hadad, though his letters invoke only Ba'alat Gubla, the "Lady of Byblos".

The Amarna letters are an archive, written on clay tablets, primarily consisting of diplomatic correspondence between the Egyptian administration and its representatives in Canaan and Amurru, or neighboring kingdom leaders, during the New Kingdom, spanning a period of no more than thirty years between c. 1360–1332 BC. The letters were found in Upper Egypt at el-Amarna, the modern name for the ancient Egyptian capital of Akhetaten, founded by pharaoh Akhenaten (1350s–1330s BC) during the Eighteenth Dynasty of Egypt.