A Synopsis of the genus Habenaria is presented for the New World species in two parts. The taxonomic status, typification, geographical distribution and taxonomic notes are presented for each species. A total of 672 names have been proposed for New World Habenaria, 298 of which are presently accepted. 235 are synonyms in Habenaria and 133 belong in other genera, mostly Platanthera. At least 22 of the accepted species are obscure or poorly understood. 107 lectotypifications, one new combination and 44 new synonyms are proposed. Brazil, with 167 taxa, has most species, followed by Mexico, with 72 species, and Venezuela with 44 species. Brazil (105 spp.) and Mexico (53 spp.) also have the greatest number of endemic species. Other apparent centers of endemism are Bolivia and Costa Rica. 205 species are restricted to a single country, but narrow endemics are few. None of the New World species occurs in other continents. The first part of the synopsis lists species in the range A—L.