Stenonartonia is a neotropical genus restricted to the forested regions of South America east of the Andes. The genus is revised here and numbers 14 species. Nine new species S. hasyva sp. nov., S. perdita sp. nov., S. cooperi sp. nov., S. guaraya sp. nov., S. rejectoides sp. nov., S. occipitalis sp. nov., S. tanykaju sp. nov., S. hermetica sp. nov., S. grossa sp. nov. are discribed and illustrated. New combination is proposed for S. mimica (Kohl), comb. nov. (from Paranortonia). Lectotype is designated for Nortonia polybioides von Schulthess. A key, along with full descriptions, illustrations of morphological features and distribution maps for all of the species are given.