Meganeuropsis is an extinct genus of griffinfly, order Meganisoptera, known from the Early Permian Wellington Formation of North America, and represents the largest known insect of all time. Meganeuropsis existed during the Artinskian age of the Permian period, 290.1–283.5 mya.^[1] The genus includes two described species by Frank Morton Carpenter, fossil insect curator at the Museum of Comparative Zoology at Harvard University:

Meganeuropsis Temporal range: Artinskian PreꞒ Ꞓ O S D C P T J K Pg N
Diagrammatic reconstruction
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	†Meganisoptera
Family:	†Meganeuridae
Genus:	†Meganeuropsis Carpenter, 1939
Species
†M. americana Carpenter, 1947 †M. permiana Carpenter, 1939

Meganeuropsis permiana described in 1939 from Elmo, Kansas. It was one of the largest known insects that ever lived, with a reconstructed wing length of 330 millimetres (13 in), an estimated wingspan of up to 710 millimetres (28 in), and a body length from head to tail of almost 430 millimetres (17 in).^[2] The holotype is held in the Museum of Comparative Zoology.^[3]

Meganeuropsis americana, discovered in Noble, Oklahoma in 1940, is most probably a junior synonym of Meganeuropsis permiana.^[4][5] It is represented by a forewing fragment 280 millimetres (11 in) long. The complete reconstructed wing had an estimated total length of 305 millimetres (12.0 in), making it the largest insect wing ever found (with a resulting wing span of 690 millimetres (27 in)).^[6] The holotype is held in the Museum of Comparative Zoology.^[7]