The new species Cololejeunea subhyalomarginata Thouvenot & Pócs, from New Caledonia, is described and illustrated. It can be distinguished from allied species like C. pseudostephanii Tixier, C. sophiana Tixier or C. elisabethae Meagher & Pócs by 1) falcate leaf lobes, 2) Allorgella-type denticulations, 3) mostly 2 ranked subhyaline border, 4) smooth cell surfaces, 5) no vitta, 6) two sub-equal triangular lobule teeth, 7) 1-celled stylus, and 8) obcordate perianth. The species is endemic to North Province of New Caledonia where it grows very scattered among other epiphylls in the highest elevations of the country.