Climate change is a key priority for European Union external action, and the EU is an important global climate actor. The EU is also committed to mainstreaming the goal of gender equality throughout all of its internal and external activities. However, EU external climate policy remains largely gender-blind. This chapter draws on feminist institutionalism and the literature on policy integration, including gender mainstreaming, to show how and why gender is excluded from EU external climate policy. It asks, firstly, where, in external climate policy, do we find references to gender and what, if anything, do they contribute to achieving gender-just climate policy. Secondly, it asks how feminist institutionalism and policy integration studies can help us understand why gender equality is not mainstreamed in EU external policy and what institutional obstacles prevent its integration. It argues that gender has been excluded from EU external climate policy by a combination of institutional power struggles; a discourse of crisis and security, which pushes gender into the background; and a proliferation of nexuses and mainstreaming imperatives in which the Treaty obligation to mainstream gender is pushed to one side.