<p>In the face of a growing plastic pollution problem, global efforts are being directed toward more sustainable solutions in the packaging sector in accordance with circular economy principles. To find more sustainable alternatives, businesses are exploring innovative types of materials and packaging such as bio-based, biodegradable, and compostable plastics. Although the development of compostable packaging applications is desirable for sustainability reasons, there is uncertainty in determining the growth trajectory of this packaging sector. The aim of this paper is to investigate the possible pathways shaped by national policy leading to the compostable packaging market expansion under uncertain conditions, in order to show enterprises and policy makers the importance of involvement in the national circular system to meet the climate policy targets. This study employed a qualitative scenario technique based on the Global Business Network planning approach and focus group interviews conducted among representatives of the Polish bio-based biodegradable packaging market to gather and assess data for describing possible future pathways. This is one of the first studies to use qualitative scenario methods to analyze the possible scenarios for the market growth of compostable packaging and to define transition pathways in relation to national policy and economic conditions. The results of this study reveal that national policy has a decisive role in the development of the compostable packaging market and the closure of its life cycle in line with the circular economy principles. It drives positive and far-reaching changes when it uses a systemic approach and considers all elements necessary for circularity. </p>