Viola tenuis Benth. was first described by George Bentham in 1842, without any type specimen designated, but with a collection record by Richard Brinsley Hinds in 1841. Currently, Viola tenuis is considered a synonym of another species according to Plants of the World Online (POWO). However, based on a combination of morphological and molecular evidence, we propose reinstating Viola tenuis as a distinct species. Our analysis places it within Viola sect. Plagiostigma subsect. Diffusae, where it shows morphological similarities to five other species endemic to Guangdong Province, China. We designated the type of V. tenuis here and assigned additional KFBG specimens to the species.