The hornets belong to the insect order Hymenoptera, which include:
The social wasps belong to the family Vespidae, which contains a great many species in 6 subfamilies, 2 of which contain mostly eusocial species.
Within the subfamily Vespinae, 4 genera are recognised:
The 3 species of Provespa are restricted to tropical Asia but the other genera are more widely distributed and species-rich.
The familiar 'yellowjackets' are found in the genera Vespula and Dolichovespula.