In the Hawaiian Islands, the genus Philonotis of the family Bartramiaceae has five species: P. hastata is pantropical, P. sullivantii is endemic to the Hawaiian Islands and P. hawaiica is new to Mexico, P. pseudomollis and P. thwaitesii are new records to Hawai'i. The Hawaiian specimens of P. falcata probably represent depauperate forms of male plants of P. sullivantii, and P. falcata is excluded from the Hawaiian flora. Philonotis turneriana is a Himalayan taxon, and is excluded from the Pacific Philonotis flora. Philonotis asperifolia, P. pseudomollis, P. thwaitesii and P. vescoana occur on several Pacific islands, P. secunda occurs in New Caledonia and Samoa and P. pyriformis on Rapa Island. Philonotis tenuis is known from Norfolk Island; it may have other occurrences in the area, but these need to be confirmed. Philonotis sharpiana is synonymized with P. hawaiica. Philonotis angustissima, P. parisii, P. praemollis and P. runcinata are synonymized with P. pseudomollis. Philonotis etessei is synonymized with P. asperifolia. Philonotis norrisii T.J. Kop. sp. nova is described. Lectotypes are selected for P. asperifolia, P. runcinata, P. sullivantii and P. vescoana. Descriptions and illustrations are provided for P. asperifolia, P. hawaiica, P. norrisii and P. sullivantii, and the taxonomy of other taxa is discussed referring to earlier descriptions and illustrations. The taxa are divided into floristic elements. Philonotis pseudomollis is the first record to Solomon Islands.