We provide the first comprehensive assessment of the Greater Antilles butterfly fauna from a molecular perspective. We gathered COI barcodes for 82% of the archipelago’s 367 species. Barcodes perform relatively well for species identification. A barcode gap separates 83% of the 270 species (represented by at least two sequences) from its nearest neighbour (NN). Of the 31 species represented by single barcodes, 26 have minimum distances from their NN above 2%. Maximum intraspecific distances are higher than 2% for 57 species (21%); however, values are lower within single islands suggesting that a part of these species has evolved into endemic lineages overlooked or unrecognized until today. Barcodes are diagnostic for only 80 of the currently accepted 180 subspecies represented by at least two sequences suggesting numerous conflicts with the infraspecific classification and highlighting its subjectivity. For 20 species, and several subspecies within them, we propose a split into two or more species and elevating several subspecies to the species category. Other data sources including novel or previously ignored morphological characters of adults and immature stages, natural history and/or additional nuclear sequences support these taxonomic changes.