Urbain-Louis-Eugène Léger (7 September 1866 – 7 July 1948) was a French zoologist who was a specialist on aquatic protists, fish parasites, and fish farming.
Léger was born in Loches, son of a school teacher.
Léger's researches included work on the Gregarinida in collaboration with Octave Duboscq.
He also studied the life-history of Cnidospora, flagellates, trichomycetes, and ciliates.
He also studied the fishes of the Dauphiné region examining habitat characteristics and was later involved in introductions of fish species into the Alps and into Madagascar.