Pierre Louis Jean Ivolas

Pierre Louis Jean Ivolas (7 April 1842, in Sète – 29 June 1908, in Tours) was a French naturalist.

A professor at the Lycée in Tours, he is remembered for geological studies of central France and botanical investigations of Indre-et-Loire. He was a good friend of botanist Ernest Henry Tourlet — Ivolas took over the completion of Catalogue raisonné des plantes vasculaires du département d'Indre-et-Loire following the death of Tourlet in 1907.

In 1879 he became a member of the Société Botanique de France. His herbarium is kept at the Herbarium of the University of Montpellier 2 Sciences et Techniques du Languedoc. With Albert Peyrot, he is the taxonomic authority of the sea snail species Eulima elongata.