This essay provides an introduction to the topic of demons and the means of opposing them in ancient Mesopotamia during the early third to late first millennia BCE. Demons and witchcraft were integrated aspects of the Mesopotamian world. They could threaten individuals, often causing illness or ill fortune, as well as target society as a whole, encroaching upon the protected and ordered world of the Mesopotamian city. There were a number of ways to counter such threats, such as protective amulets and incantations, but the foremost, particularly in the first millennium BCE, was the figure of the ašipu, or exorcist. A trained ritual professional, the ašipu had a range of tools at his disposal, as well as the protection and sanction of the gods. This article provides an introduction to the issue of demons and exorcism by presenting four key aspects of this complex topic: first, an overview of characteristics and role of demons in Mesopotamia; second, a summary of the two notable demonic figures known as Lamashtu and Pazuzu; third, the demonic and chaotic figure of the witch; and fourth, an overview of the ašipu and his methods. 1 | A TYPOLOGY OF DEMONS The cultures and societies of ancient Mesopotamia, a region which ranged geographically from the Assyrian north to the Babylonian south and chronologically from the third to late-first millennia BCE, were populated by a range of monstrous or supernatural figures, found in an diverse array of both quantity and kind. These beings were an integrated aspect of Mesopotamia's different societies, with textual attestations found throughout its histories. Over the veritable millennia, these figures could and did take on different shapes and forms, and the measures designed to counter them evolved alongside these changes. This article presents an overview of these beings, as well as other supernatural threats, such as the figure of the witch, that they existed alongside. Given the range of locations and wide chronological span under review, this article