Léon Marc Herminie Fairmaire (29 June 1820 – 1 April 1906) was a French entomologist.
A specialist in Coleoptera he assembled an immense collection comparable with that of Pierre François Marie Auguste Dejean (1780-1845). This is in the Muséum national d’histoire naturelle. Fairmaire wrote 450 scientific papers and other publications relating to Coleoptera (partial list of papers in Wikispecies). He also worked on Hemiptera.