Jules Thurmann (5 November 1804, Neuf-Brisach in Haut-Rhin, France – 25 July 1855, Porrentruy) was an Alsatian French-Swiss geologist and botanist.

He studied at the college in Porrentruy, then continued his education at the University of Strasbourg and at the École royale des mines in Paris.

He devoted much of his time to geological studies of the Jura Mountains, being known for his pioneer investigations in regards to Jurassic orography.

[2] In the field of stratigraphy, he introduced in 1834 the term "Neocomian" to define the lowest stage of Cretaceous formation.

[3] As a botanist, he conducted phytosociological research,[2] and is credited with directing the last phases of development for the botanical garden at Porrentruy.