Promecotheca cumingii is a species of beetle of the family Chrysomelidae. It is found in China, Indonesia (Borneo, Sulawesi, Java), Malaysia, the Philippines (Leyte, Luzon, Mindanao, Palawan, Samar), Singapore and Sri Lanka.
The recorded host plants for this species are Cocos nucifera, Nypa fruticans, Metroxylon and Caryola species, as well as Oreodoxa regia.