Presented here is a taxonomic revision of the Neotropical palm genus Syagrus (Arecaceae, Arecoideae, Cocoseae, Attaleinae), which is mostly from South America and primarily from Brazil. The history of the genus is reviewed. The revision includes a key, a complete list of synonymy, species descriptions, a list of specimens, distribution maps, color plates, and a conservation assessment of each species. Included herein are 65 species, 2 subspecies, and 14 natural hybrids. Of these palms, one is new (Syagrus pimentae); three are new combinations (S. cataphracta, S. elata, S. × dickensonii); and two have changed their status (S. graminifolia subsp. graminifolia and S. graminifolia subsp. glazioviana). Of the fourteen naturally occurring hybrids, eleven have hybrid names and three do not. This revision is an important contribution to the taxonomy and identification of Syagrus species from South America and the Caribbean, and is the culmination of many years of lab and fieldwork.