Orientalist, polyglot and scholar, he wrote the famous Voyage du jeune Anacharsis en Grèce..., which was translated into various European languages (as the Travels of Anacharsis the Younger in Greece in English) and became a manifesto of the revival of the Hellenistic style. Thanks to his knowledge of Arabic and his works on the Phoenician language (of which he was the first to translate an inscription), he was appointed "Garde du Gabinet des médailles de la Bibliothèque du Roi." In 1755 his classical studies led him, at the invitation of the French ambassador, to undertake a journey to Italy to see the archeological treasures in the great Italian collections.

In the Voyage en Italie de M. l'Abbé... (Paris, Buisson, 1801), a volume made up of forty-nine letters written by Barthélemy to the count of Caylus, we find interesting information on the scholar's journey. The work is particularly fascinating owing to the attention it focuses on the classic world and to the relationship between Barthélemy and the French scholar Caylus. In the volume Mémoires sur la vie et quelques-uns des ouvrages de J.-J. Barthélemy..., l'autore sposta la sua attenzione dall'antichità the author shifted his attention from antiquity to the Italian Cinquecento, cradle of the Renaissance. His erudite reputation led to his election to the French Academy, but his prodigious career was cut short by the outbreak of the Revolution.