Millepora dichotoma is a branching fire coral (family Milleporidae) found in shallow Indo-Pacific reef environments, particularly common in the Red Sea, Indian Ocean, and western Pacific, forming irregularly dichotomous branches with a pale, cream-colored calcareous skeleton housing numerous stinging polyps. It is one of the major reef-building organisms in the Red Sea, where it can form dominant monospecific stands on shallow reef crests. The large genome size in Millepora species is a notable feature distinguishing this hydrozoan lineage from most other cnidarians and is an active subject of genome evolution research.