Teluk Sulaman, Sabah, is a secluded area that is rich in biological resources but with minimal biodiversity information. Small scale mud crab fisheries exist in Teluk Sulaman to support local livelihood, but there is a tendency of overfishing due to the increasing demand of this resource. The diversity of mud crab in Teluk Sulaman is still unknown. Information on the diversity of mud crab is vital, not only for conservation purpose but also to support the utilisation of this valuable resource sustainably. Therefore, this study aimed to identify the species of mud crabs in Teluk Sulaman, using morphological and molecular approaches. Based on morphological data, Teluk Sulaman only supports one species of mud crab, namely Scylla tranquebarica. The 460 bp 16S rRNA gene obtained in this study matched S. tranquebarica (GenBank Accession No.: KM258653.1), thus supported the conventional method of species identification. The phylogenetic trees agreed that S. tranquebarica is monophyletic. However, the relationship between S. serrata and S. olivacea remains unresolved. Future studies should explore spatial and temporal sampling besides using other genetic markers to further understand mud crab population in Teluk Sulaman further.