Louis Pierre Vieillot (; 10 May 1748 in Yvetot - 24 August 1830 in Sotteville-lès-Rouen) was a French ornithologist.

Vieillot is the author of the first scientific descriptions and Linnaean names of a number of birds, including species he collected himself in the West Indies, as well as North American and South American species discovered but not formally named by Félix de Azara