An inventory of the sponge fauna from the Singapore Strait to the Taiwan Strait along the western
coastline of the South China Sea was compiled from published and grey literature from the following regions: Singapore, peninsular Malaysia, Thailand, Cambodia, Vietnam, southern China and Taiwan. This study provides a partial update to the “Checklist of sponges (Porifera) of the South China Sea region” published 15 years ago. A total of 388 sponge species belonging to 24 orders, 78 families and 158 genera are listed, with the following regional species diversities: Singapore (130); east coast of peninsular Malaysia (25); Gulf of Thailand (90); Vietnam (141); southern China (138); and Taiwan (64). A total of 12 new species and over 200 new records were added to the Porifera inventory of the South China Sea since 2001. Of the 388 species, only 16 species (4%) are widespread. They are: Aaptos suberitoides, Acanthella cavernosa, Biemna fortis, Cinachyrella australiensis, Clathria (Thalysias) reinwardti, Coelocarteria singaporensis, Echinodictyum asperum, Hyrtios erectus, Haliclona (Gellius) cymaeformis, Iotrochota baculifera, I. purpurea, Mycale (Zygomycale) parishii, Neopetrosia exigua, Oceanapia sagittaria, Spheciospongia vagabunda, Xestospongia testudinaria. Only X. testudinaria, M. (Zygomycale) parishii and C. australiensis are present along the entire coastline from Singapore Strait to Taiwan Strait. Distinct sponge faunal assemblages occur between the equator and 25°N along the western coastline of the South China Sea.