He began his career with an edition and commentary of Festus's De verborum significatione, and was the first to produce a "readable" text of the 20-book work.

[2][3] In 1695 he was elected to the Academy of Inscriptions, and also to the Académie française; not long after this, as payment for his share in the medallic history of the king's reign, he was appointed keeper of the library of the Louvre.

[4] The most important of Dacier's works were his editions of Pompeius Festus and Verrius Flaccus, and his translations of Horace (with notes),[5] Aristotle's Poetics, the Electra and Oedipus the King of Sophocles; Epictetus, Hippocrates and Plutarch's Lives.

[4] Dacier and his wife Anne together translated Meditations by Marcus Aurelius into French in 1690–91, as well as writing an extensive commentary on the work.

Addressing his work to the Dauphin (in usum Delphini), at that time Louis, he was more interested in the realia of Roman law, treaties, and the foundations of power than in the literary quality of the text or its lack thereof.