The crustose Roccellaceae, excluding Opegrapha, on the Galapagos Islands were investigated. In total, 24 species were identified, most of which are new records not only for the archipelago, but also for Ecuador. These include Schismatomma spierii, which is described as new to science. Lecanographa laingiana is reported for the first time from the New World and Bactrospora denticulata, Dirina catalinariae, Lecanographa hypothallina, L. illecebrosula, Sclerophyton murex and S. vertex are first records from the Southern Hemisphere. Previous records of Roccellina from the Galapagos are regarded as erroneous. A key to the species is provided.