This revision of Davallia starts with a chapter about the morphology of the genus. In Davallia two sections are recognized, section Davallia and the new section Scyphularia. The species formerly belonging to Araiostegia, Humata and/or Pachypleuria are incorporated in Davallia. Thirty-four species are described, with one new, Davallia rouffaeriensis, and five new combinations or states are made. Keys to the genera (of the family Davalliaceae) and the species (of Davallia) are given. An index to all treated species (and their synonyms) is given.