As part of the Paris Agreement, countries are asked to put forward their nationally determined contributions (NDCs), which present their proposed pathways to tackle climate change. To that end, circular economy (CE) has been proposed as a potentially important catalyzer to meet NDCs. Yet, the potential of CE strategies to help reach climate goals at the country scale has been little explored until now. Here, we propose a consistent step-wise methodology, which assesses quantitatively the potential of CE strategies to reach national targets for GHG emission mitigation. Projections of a given country’s business-as-usual (BAU) emissions are derived to pinpoint key emitting sectors and link those with relevant CE strategies identified from the literature that can mitigate their emissions. The resulting mitigation potentials can be compared to different national benchmarks to serve policy making processes. Although applicable to any countries, we focus on applications to developing countries, which often lack structured approaches and efficient mechanisms to integrate their climate objectives into national strategies and policies. As proof-of-concept, we thus applied the methodology to the case of Chile. For this country, the proposed sector-specific CE measures were found to potentially reduce by 37% the GHG emissions in 2030 compared to BAU levels, thus putting the country on track to fulfill its NDC commitments. Building on this proof-of-concept and discussions from its run, we recommend the application of our methodology to other countries to identify CE opportunities and enable capacity building to support policy making.