This thesis examines democratic transitions that occur in the context of international administration, where international actors not only provide assistance and guidance regarding domestic development, but also hold temporary executive authority over some or all of the functions of government. It argues that the process of regime change in the context of international administration is systematically different from more conventional settings, where such extensive international intervention is absent. The theoretical framework of the thesis suggests that the most significant impact of international administration derives from the fact that external actors assume roles conventionally held by domestic actors, and thus have available to them extensive mechanisms of influence at the domestic level. International agents can favour some local elites over others, structure the political environment through agenda-setting and veto powers, and ultimately bypass local actors if deemed necessary by drafting and imposing laws and institutions. As a result, the presence of international administrators heavily shapes the final mode of transition, and one of the most significant implications of the external influence is that purely non-democratic regime outcomes are unlikely to emerge. However, the influences of international administration are not always positive, and neither are they constant across contexts. The final impact on the transition process itself will depend in large part on the nature of the domestic political landscape, and in particular the balance of power and ideology among the domestic political parties. When domestic elites are favourable to democracy, international administrations can work with local actors to co-author a new democratic regime through a pacted transition. When dominant local parties are opposed to democratic development, however, the international and domestic interaction may contribute to a more conflicrual and contentious mode of transition entailing elements of international imposition. The nature of the transition mode will, in turn, have implications for post-transition regime consolidation. These findings are based on a structured, focused comparison of three cases, those of Bosnia, Kosovo and East Timor. In attempting to isolate the international influence, the case studies utilise the process tracing method to identify the causal mechanisms that connect international actions to democratic political outcomes, and the experiences in each case are compared to facilitate the generation of bounded generalisations about the impact of international administration on the processes of regime change.