Domenico Agostino Vandelli (Padua, 8 July 1735 – Lisbon, 27 June 1816) was an Italian naturalist, who did most of his scientific work in Portugal.
He studied at the University of Padua, from which he received a doctorate in Natural Philosophy and Medicine in 1756.
One of his major works he published was the Tractatus de thermis agri patavini in 1761.
In about 1793 he became the first director of the Botanical Gardens at the Palácio da Ajuda in Lisbon.
He was one of the mentors of the Sciences Academy of Lisbon.In the field of herpetology he is best known for having described the world's largest living turtle, the leatherback sea turtle (Dermochelys coriacea).
Domenico Agostino Vandelli should not be confused with Domenico Vandelli (1691-1754), an Italian cartographer, scientist, and mathematician.