Males of the araneid genus Cyrtophora Simon 1864 are comparatively rare in collections, possibly because they are much smaller and less conspicuous than their female counterparts and are expected to have a much shorter lifespan. Field work on Christmas Island (Indian Ocean) revealed a male of Cyrtophora unicolor (Doleschall 1857) copulating with a female. Both male and female are described here. The known distribution of C. unicolor is updated to include southern parts of China, Taiwan and Japan in the North, the Philippines and Papua New Guinea to the south-east, Indonesia and Christmas Island to the South, and Thailand, Myanmar, and Sri Lanka to the East. Cyrtophora acrobalia (Thorell 1895), described from a juvenile from Myanmar, is considered a nomen dubium.