A recent phylogenetic study based on molecular data indicates that Licuala (Arecaceae: Palmae) is not monophyletic. A highly supported group of species is resolved separately from Licuala and the rest of the Livistoninae, and is closely related to Johannesteijsmannia, requiring that the segregate group be placed in a new genus. In this study a phylogeny based on seven gene regions resolves highly supported generic relationships of the Livistoninae. A survey of Licuala specimens from several herbaria indicates that, based on morphology, eight species should be recognized within this genus. A complete description of the new genus, Lanonia, is given. A review of morphology distinguishes synapomorphies in leaf morphology and dioecy of Lanonia species. All eight species are described with complete synonymy, their distributions are mapped, and lists of specimens examined are given. One species occurs in Hainan, one in Java, and six are endemic or nearly endemic to Vietnam. The following new combinations are made: L. acaulis, L. calciphila, L. centralis, L. dasyantha, L. gracilis, L. hainanensis, L. hexasepala, and L. magalonii.