Hypolepis is a subcosmopolitan genus with ca. 80–90 taxa worldwide, and with few taxonomic studies. The present work is a taxonomic revision of the South American species, including Cocos Island (Costa Rica). It has been based, mainly, on the morphological study of nomenclatural types and exsiccates from European and South American herbaria, plus one herbarium from New Zealand and another from the United States of America. Some species were also studied in nature. For South America (incl. Cocos Island), 26 species are here recognized, and a total of 31 taxa (species, subspecies, varieties, and hybrids). Among these are four new taxa: H. galapagensis, H. ×glabra, H. ×paulistana, and H. pedropaloensis. The geographical distribution patterns were classified into nine categories. Minimum and maximum elevations are strong limiting factors of distribution. The taxonomic treatment includes keys to taxa, new and complete synonymies, typifications, taxa description, distribution maps, illustrations, studied material, and taxonomic and/or nomenclatural comments. In addition, there are short discussions about morphology and biogeography.