Ephraim Porter Felt (7 January 1868 Salem - 14 December 1943) was an American entomologist who specialised in Diptera
Ephraim Felt worked mostly Nematocera and particularly Cecidomyiidae.However he was the State Entomologist New York State and so worked with all insects of economic or medical significance. He wrote Insects affecting park and woodland trees. New York State Museum Memoir 8 (1905-1906) and Plant galls and gall makers Ithaca, N.Y., Comstock Pub. Co. (1940) as well as describing over 1,000 species in scientific journals. The holotypes of the Felt named insect species are in the National Museum of Natural History. Felt was the author of the mosquito genus Culiseta.