He represented his family's business interests in Saint-Domingue (Haiti) on Hispaniola, but fled to the United States during the Haitian rebellions that followed the French Revolution.

On Buffon's advice, he collected material for the Histoire naturelle des oiseaux de l'Amérique Septentrionale, the first two volumes of which were published in France beginning in 1807.

Vieillot returned to France for the last time in 1798, where the position created for him at the Bulletin des Lois left him sufficient leisure to continue his natural history studies.

Vieillot's Analyse d'une nouvelle Ornithologie Elémentaire (1816) set out a new system of ornithological classification, which he applied with slight modifications in his contributions to the Nouveau dictionnaire d'histoire naturelle (1816–1819).

There was bitter rivalry between the leading ornithologists and the classification introduced by Vieillot was strongly criticized by Coenraad Temminck in a pamphlet published in 1817.