Globally, scleractinian coral diversity peaked in the Early Miocene (Burdigalian) and declined afterwards. In contrast to this global trend, scleractinian coral diversity in the Lower to Middle Miocene was low in the Red Sea, which had begun to open in the Oligocene and experienced its first marine incursion in the Burdigalian. Here, we report on coral diversity of reefs assigned to the Burdigalian to Langhian Wadi Waqb Member (Jabal Kibrit Formation) from outcrops exposed in the foothills behind the Red Sea coastline near Umluj, Saudi Arabia. Compared to the global records from the Paleobiology Database and the literature, the fossil record from the Wadi Waqb member suggests a relation of the taxonomic spectrum to the Arabian Gulf and the Mediterranean. No clear relation to the taxonomic spectrum to the Indian Ocean is observed. These faunal differences are consistent with the hypothesis that the young Red Sea was connected to the Arabian Gulf via the Mediterranean through the Gulf of Suez, but there was no connection between the Red Sea and the Indian Ocean because of the Afar mantle plume that uplifted the southern area of the Red Sea rift and blocked direct exchange of marine biota.