After completing her secondary education and starting university in Luxembourg, J. Scheid discovered research in ancient history at the University of Strasbourg, then during his Master's degree at the Sorbonne. During his studies at the École pratique des hautes études, he was influenced by two fields of research, prosopography (H.-G. Pflaum) and the history of religions in Greco-Roman antiquity (R. Schilling, J.-P. Vernant, M. Detienne).
Having decided to take this path, he passed the agrégation after acquiring French nationality, and was a member of the École française de Rome from 1974-1977. He decided to devote his doctoral thesis to the senatorial brotherhood of the Arvales brothers, which had been the subject of a doctoral dissertation (IIIe cycle) he had defended in 1972. From 1975 to 1998, he also directed excavations at the sanctuary of the arvales brothers on the outskirts of Rome, and worked at the Museo Nazionale dei Terme on the rich collection of their epigraphic accounts, which he was to re-edit.
During the twenty years he spent at theV section of the École pratique des hautes études, he specialized in the religions of Rome. His election to the Collège de France in 2000 enabled him to also teach on institutions, notably the imperial regime, or Roman society, in accordance with the title of his chair, while avoiding breaking the link with ancient texts, inscriptions and the archaeology of places of worship, which he practiced until 2012. He believes that direct documentation rather than literary texts alone is essential to understanding the institutions and, in particular, the religions of the ancient world, which are so different from Christianity.