The genus was first erected as Liuixalus in 2008 based on molecular genetic evidence showing distinctness of Liuixalus romeri (then known as Chiromantis romeri) from the rest of Chiromantis. The genus name Liuixalus commemorates Liu Chengzhao[zh], a Chinese herpetologist. In 2021, another phylogenetic study deemed the name Liuixalus as invalidly proposed due to a lack of a diagnosis for the genus in the original study, and thus redescribed the genus as Romerus, alongside morphological characteristics distinguishing it. The name Romerus commemorates British herpetologist John D. Romer. However, in 2023, the name was changed back to Liuixalus on the basis of Ren, Jiang & Li, who refuted the requirement for a genus name to have morphological characteristics associated with it.
12Li, J. T.; Che, J.; Bain, R. H.; Zhao, E. M.; Zhang, Y. P. (2008). "Molecular phylogeny of Rhacophoridae (Anura): A framework of taxonomic reassignment of species within the genera Aquixalus, Chiromantis, Rhacophorus, and Philautus". Molecular Phylogenetics and Evolution. 48 (1): 302–312. doi:10.1016/j.ympev.2008.03.023. PMID18442928.