Aristophanic comedy contains prominent references to practices modern English-speakers might label ‘expulsive,’ e.g., the ritual removal of the φαρμακός (‘human scapegoat’) from Athens. However, there is no reason to assume that archaic and classical Greeks conceptualized the distinction between ‘expulsive’ and ‘non-expulsive’ practices in the same way we do today. Understanding the implications of comedy’s expulsive references therefore requires understanding the cultural contexts of what we call ‘expulsion.’ To gain such an understanding, I devoted two chapters to archaic and classical expulsion. In Chapter 1, I surveyed the historical evidence for five formal practices: scapegoat ritual, ostracism, ἀτιμία, outlawry, and death-related expulsions. In Chapter 2, I turned to poetry and examined references both to these five practices and to less formal events of the same nature. With the characterization of expulsion I derived from these sources, I moved onto the main object of my analysis: comedy. In Chapter 3, I examined comic prehistory, as well as Aristophanes’ first two surviving plays, Acharnians and Knights, and identified many passages pertaining to expulsion. In Chapter 4, I did the same for Aristophanes’ Birds, the play with the most episodic scenes, common focal points for comic expulsion. The surveys in the first two chapters found many points of contact between various ‘expulsive’ practices regardless of whether the departure was voluntary on the part of the expelled or even intended by the persecutors. Chapter 3 highlighted the importance of hostility in comic prehistory, discerned an expulsive plot arc spanning Acharnians, and identified many isolated passages relating to expulsion in Knights before its highly expulsive ending. Chapter 4 discerned in Aristophanes’ Birds an expulsive plot arc like that of Acharnians yet grander in scale. From these investigations, I concluded that archaic and classical expulsion should be understood more broadly than the modern term implies and that expulsion is one important key among many to understanding Aristophanic comedy, sometimes unifying entire comic plots.