This article explores the encounter between the Women, Peace and Security agenda and rebel institutions in Mindanao. The analysis highlights that activities aiming to support women’s participation in peacebuilding often exist in parallel with and fail to fully recognise women’s existing forms of mobilisation within Non-State Armed Groups. This gap is bridged by civil society brokers who are associated with armed groups but speak the language of international peacebuilding frameworks. The findings point to the important role of such intermediaries in translating international norms, and to rebel groups and institutions as arenas for women’s political mobilisation and empowerment.