International Public Administrations (IPAs), that is, the secretariats of international organizations, are important actors in global governance. This article develops a new typology of IPAs that captures the potential influence of these bureaucratic bodies on international policy‐making. The main argument is that when conceptualizing the varying roles and potential policy impact of IPAs, it is useful to distinguish between their ability to develop autonomous preferences (autonomy of will) on the one hand, and their capacity to transform these preferences into action (autonomy of action) on the other. Based on this premise, the article introduces four distinct ideal‐types of international bureaucracies and suggests indicators to locate a diverse sample of 20 administrations within the four‐fold typology. The results reveal the empirical diversity of IPA autonomy and allow for a first empirical assessment of the factors behind this pattern.