We report on a green turtle, Chelonia mydas, captured along central coastal Queensland, Australia, that had a cloacal opening on the dorsal side of its tail. Here we describe the internal anatomy and possible embryonic development of this abnormality and discuss the functional and reproductive implications for this turtle. To our knowledge, this is the first report of an ectopic cloaca (supra-caudal vent) deformity occurring within any turtle, tortoise, or terrapin species.