Jean-Louis-Auguste Loiseleur-Deslongchamps (24 March 1774, in Dreux, Eure-et-Loir – 8 May 1849, in Paris) was a French physician and botanist.

The standard author abbreviation Loisel.

[1] He was the author of and contributor of a number of works on medicine and botany.

He was elected to the Académie Nationale de Médecine in 1823 and was made a Chevalier of the Legion of Honour in 1834.

He is commemorated with the botanical genera Loiseleuria (Desv., 1813) and Longchampia (Willd., 1811).