The Homerus swallowtail or Jamaican giant swallowtail (Papilio homerus) is the largest swallowtail butterfly in the Western Hemisphere and the largest species in the genus Papilio with an average wingspan of about 15 centimetres (5.9 in) (the African giant swallowtail has a larger wingspan, but this is mainly due to its elongated forewings). The Homerus swallowtail belongs to the swallowtail family (tribus: Papilionini) and is often placed in the subgenus Pterourus, considered a full genus by some authors.