Publication details and bibliographic and distributional information are provided for the lichens of 33 island groups and isolated islands in the Pacific Ocean between latitudes 40°N and 40°S. A total of 280 genera are listed, with 2189 accepted species and intraspecific taxa and 1425 synonyms; 743 of the accepted taxa are based on type specimens from the region. Checklists are presented for each island group and isolated island, and a bibliography of more than 450 entries is provided. While the Hawaiian Islands have by far the largest known flora (885 taxa), more than 100 taxa have been reported from each of the following: New Caledonia (604), Islas Juan Fernändez (254), Islas Galäpagos (229), the Society Islands (221), Western Samoa (182), Fiji (118), Norfolk Island (111), Isla del Coco (109) and Lord Howe Island (102).