Circular economy principles are already widely adopted in the civil sector, however, the defence sector lags behind, facing several challenges that hinder its uptake. Western countries are increasing defence expenditures despite financial constraints, resulting in a steady rise in carbon emissions from military processes. Circular economy practices, which are not yet widespread in this sector, present an attractive long-term solution to both these concerns. In a turbulent security landscape, amid an environmental crisis, a shift from the ‘take-make-waste’ (Knight, 2023) approach to a circular economy model is crucial as it offers the sector economic resilience, autonomy, operational efficiency and civil-military synergies in times of instability, strengthening the sector overall. As the European Defence Agency argues, ‘strengthening Europe’s security capabilities is a challenge that requires strategic planning and an efficient use of resources’ (Katainen, 2016). The Incubation Forum for Circular Economy in European Defence (IF CEED), established by the European Defence Agency in 2021, plays a crucial role in applying the circularity principles of the EU Green Deal to the European defence sector (European Defence Agency, 2023). The goal of the IF CEED is to apply principles and policies from the civilian sector to the defence sector, under the premise that a European circular economy can only be achieved through the participation of all sectors (European Defence Agency, n.d.). This paper starts with the definition of circular economy. It then analyses the current state of military expenditure and carbon emissions. Finally, it presents three project ideas of the IF CEED – Circular Data, Additive Manufacturing and Circular Materials for Textiles (European Defence Agency, n.d.) and the value they bring to the European defence sector.