Stiphodon sapphirinus, new species, is described on the basis of material collected from New Caledonia. It is distinguished from all other congeners in having nine segmented rays in the second dorsal fin, an elongate and filamentous fourth dorsal spine that lacks membranous tissue, usually 14 pectoral rays, 31-51 fine tricuspid premaxillary teeth, and sexual differences related to symphyseal teeth (0-2 small teeth in females vs 1-4 stout teeth in males), predorsal midline (usually absent in males and conspicuous in females), scales in transverse forward series, distribution of belly scales (absent in males and cycloid scales present in females) and colour pattern (males with a blue head and cobalt blue sides).