The new paradigm of the Circular Economy-CE appeared in the last decades as a response to the growing demand for sustainability, understood as a way to balance both economic, and environmental and societal aspects. Circular Economy, indeed, could change the traditional economic model, typically called Linear Economy. Within this transition, Green Public Procurement could help the developed economy worldwide to reach this goal. The paper is an international comparison on the main features of GPP policies within the CE framework of a sample of EU countries, China, Japan, and USA. The research was carried on combining interviews with experts and desk research. The main evidence is that EU and Eastern countries are leading countries in CE policies. Regarding GPP implementation, differences emerge within Europe, especially in federal states. Besides this, China, and USA suffer a not-organic regulation approach. Concluding, authors suggest to deep the barriers and drivers on GPP by international comparison with different regional contexts with a higher number of informants. This could help both policymakers and academia for further development of public policies.