Cuculus is a genus of cuckoos which has representatives in most of the Old World, although the greatest diversity is in tropical southern and southeastern Asia. The genus name is from Latin Cuculus, "cuckoo" The species in taxonomic order are: Some sources also include the pallid cuckoo in this genus, although there is disagreement about appropriate classification. The hawk-cuckoos are now placed in a separate genus, Hierococcyx, while the pallid cuckoo belongs in Cacomantis.