Based on material acquired from Green Island, Taiwan, using a combined approach of traditional morphology-based taxonomy and molecular barcoding, we describe a new species of coral-dwelling crab, Opecarcinus ngankeeae sp. nov., from the scleractinian hosts Pavona decussata and P. varians (family Agariciidae). The DNA sequences of the present species matched with O. sp. SET6, associated with plate-forming Leptoseris and Pavona corals, available on Genbank, provided by Xu et al. (2022). The geographical distribution of O. ngankeeae sp. nov. spans from the Coral Triangle and Taiwan to Japan in West Pacific.