A new genus and species within the family Xanthidae MacLeay, 1838, are described from coral reefs in the South China Sea. The new genus, Gothus, with its type species G. teemo sp. nov., is distinguishable from allied genera by characteristics of the carapace, chelipeds, and male pleon. Based on morphological evidence, we tentatively place this genus within the subfamily Euxanthinae Alcock, 1898. However, molecular systematic analysis based on COI, 12S, 16S, and H3 indicates that it does not form a stable monophyletic group with any related subfamily. Another species, Actaeodes consobrinus (A. Milne-Edwards, 1873), is also reclassified into this new genus, based on both morphological and molecular evidence.