Baron Michel Edmond de Selys Longchamps[a] (25 May 1813 – 11 December 1900) was a Belgian Liberal Party politician and scientist.

There were also systematic works containing phylogenetic analyses, tables and keys) of the "Gomphines", Calopterygines", Agrionines", "Cordulines" and ( generic only) "Aeschnines", the only family not so treated being the difficult "Libellulines".

Selys met and began a collaboration with Hermann August Hagen in 1845; They jointly produced the Revue and two monographs.

Aware of being an "homme distrait" (distracted man), Selys often affixed names to undescribed species in his collection (nomina nuda).

His collection is in the Royal Belgian Institute of Natural Sciences, although there are de Selys types in many other museums, including the Hope Department of Entomology, University of Oxford.