Claude Casimir Gillet (19 May 1806 in Dormans, department of Marne – 1 September 1896 in Alençon), was a French botanist and mycologist.
Around 1853 he developed a passion for mycology, subsequently publishing a number of works on the subject.
In 1867 he became a corresponding member of the Société Linnéenne de Normandie.
[2] Gillet was the taxonomic authority of the genera Tubaria (initially named a subgenus of Agaricus by Worthington George Smith) and Microglossum.
[3][4] He was honoured in 1899, when botanists P.A.Saccardo & P.Sydow published Gilletiella, which is a genus of fungi in the class Dothideomycetes.