Galactia watsoniana W. C. Holmes & Singhurst (Fabaceae, Papilionoideae), endemic to the southern part of the Balcones Escarpment of central Texas, is described as new. The new species is distinguished from G. volubilis (L.) Britton, its apparent nearest relative, by its solitary and larger flowers (17–22 mm vs. 6–12 mm), strigillose trichomes on plant surfaces, presence of a narrow white border on the leaflet margins, and ovate leaflets with reticulated abaxial surfaces.