This chapter looks at the Chaldean Oracles, a set of hexameter texts from the Antonine period which develop an ambitious system of Platonising theurgy. Scholars have long appreciated the importance of this corpus for the development of Neoplatonic philosophy, and late paganism more generally, but have had less to say about its place in the history of Chaldean thought – the topic of this chapter. It first traces the history of what ancient observers called the ‘philosophy’ of the Chaldeans in relation to developments in Greek philosophical thought. It then shows how the Oracles attempt to reform the Chaldean brand in response to the rise of Platonism. Finally, it places the Oracles in the cultural and intellectual context of Syria during the Antonine period. Chaldeanism emerges from this argument as a non-Greek tradition that interacted closely with the major Greek philosophical schools of its time.