Louis-Joseph Alcide Railliet (also known as Alcide Railliet, born 11 March 1852 at La Neuville-lès-Wasigny in the Ardennes – died 25 December 1930) was a French veterinarian and helminthologist.

Professor at the Veterinary School of Alfort, he is considered one of the founders of modern parasitology and wrote several books of veterinary parasitology.

He was a member of the French Académie Nationale de Médecine, from 29 December 1896 to his death.

Railliet's name is honoured by several genera: Raillietia (Acari), Raillietina (Cestodes), Raillietascaris, Raillietnema and Raillietstrongylus (Nematodes), Raillietiella (Pentastomida), and the Acari family Raillietiidae.

All these animals are parasites, named in honour of Railliet by other parasitologists (the list of species may include synonyms).