Arachnides recuellis en 1882-1883 dans la Patagonie méridionale, de Santa Cruz à Punta Arena, par M. E. Lebrun, attaché comme naturaliste à la Mission du passage de Vénus

Eugène Simon (30 April 1848 – 17 November 1924) was a French arachnologist. His many taxonomic contributions include categorizing and naming many spiders, as well as creating genera such as Anelosimus, Psellocoptus and Phlogius.

He also had an interest in hummingbirds. He described several species and races as well as creating the genera Anopetia, Stephanoxis, Haplophaedia and Taphrolesbia. He is commemorated by race simoni of the Swallow-tailed Hummingbird (Eupetomena macroura). His seminal work on hummingbirds was Histoire Naturelle des Trochilidae in 1921.

His most significant work was Histoire Naturelle des Araignées (1892), an encyclopedic treatment of the spider genera of the world.

The International Society of Arachnology offers a Simon Award recognising lifetime achievement.[1] Simon's works are in the public domain in both France and the United States.