Over the past decades, the European Union (EU) has confronted multiple crises, which have required swift political responses from the EU’s member states and institutions. While there is a broad literature about the EU’s internal responses to the polycrisis, we possess much less systematic knowledge on how the EU interacts with other international institutions to address crisis-related challenges. Since the EU is part of wider, issue-specific regime complexes, it has cultivated diverse relationships with other international organizations (IOs) across a multitude of issues. During periods of political crisis, the EU faces different incentives to complement its internal crisis response by reaching out to external actors. We identify four different types of crisis-induced relationships the EU entertains with IOs in a particular regime complex: pooling, division of labor, competition, and co-existence. To explain which of these relationships characterizes an issuespecific crisis response, we highlight two dyadic-level conditions: the extent of institutional overlap between the EU and the respective IO on the one hand, and the extent to which the crisis-response strategies of the EU and the respective IO converge. To illustrate the usefulness of our typology and the plausibility of our account, we empirically map and analyze four instances of EU-IO relationships in crisis situations: pooling among the EU and IMF to address the sovereign debt crisis; division of labor among EU and NATO in response to Russia’s war of aggression against Ukraine; co-existence among the EU and the AIIB in the context of managing the financial fallout of the Covid-19 pandemic; and competition among the EU and the ECtHR in view of the ‘migration crisis’.