Narcisse Théophile Patouillard (2 July 1854 – 30 March 1926) was a French pharmacist and mycologist.
He was born in Macornay, a town in the department of Jura. He studied in Besançon, then furthered his education at the École Supérieure de Pharmacie in Paris, where in 1884 he earned a diploma with a doctoral thesis involving the structure and classification of Hymenomycetes called "Des Hyménomycètes au point de vue de leur structure et de leur classification".
Patouillard was a practicing pharmacist for more than forty years, first in Poligny (1881–84), and later in Fontenay-sous-Bois (1884–85), Paris (1886–1898) and Neuilly-sur-Seine (beginning in 1898). From 1893 to 1900, he was préparateur to the chair of cryptogamy at the École Supérieure de Pharmacie in Paris. In 1884 he was one of the founders of the Société mycologique de France and served as its third president in 1891-92. In 1920 he became an honorary member of the British Mycological Society. He died in Paris, aged 71.
Patouillard is highly regarded for his taxonomical work in mycology, and during his career, he described numerous genera and species of fungi. The following are some of the genera that he is the taxonomic authority of: Guepiniopsis, Hirsutella, Lacrymaria, Leucocoprinus, Melanoleuca and Spongipellis. A mycological species called Inocybe patouillardii (brick-red tear mushroom) is one of the species named after him.