The genus Tainonia comprises unusually large pholcids endemic to Hispaniola. Previously, only the type species had been formally described, represented in collections by no more than 12 adult specimens. However, the existence of more species has been hypothesised based on a few further individuals. The present paper is based on a sample of 205 mostly newly collected adult specimens from 18 localities in the Dominican Republic and four localities in Haiti. The increased sampling reveals a wide range of variation, including intermediate levels of divergence that often blur rather than clarify species limits. Therefore, although not all taxonomic questions can be settled here, morphological (including morphometric) and molecular (mitochondrial 16S, CO1) data strongly support two new species: one in La Visite National Park, Haiti (T. visite, sp. nov.) and another on Samaná Peninsula and parts of the eastern Dominican Republic (T. samana, sp. nov.). Species limits among the other populations are more difficult to support or reject. Specimens from Bayahibe (eastern Dominican Republic) and from La Ciénaga (Cordillera Central) are each assigned species status on the basis of consistent morphological differences (T. bayahibe, sp. nov., T. cienaga, sp. nov.), but no molecular data are available due to lack of specimens. All other specimens are provisionally assigned to a possibly paraphyletic T. serripes (Simon). There is considerable morphological variation within this widely distributed group of populations but this variation is rather continuous and molecular distances fill most of the range between morphologically unambiguous conspecifics and unambiguous heterospecifics.