This chapter seeks to advance the fragmented discourse on the development of the global sustainable packaging sector, focusing on how packaging manufacturing evolves within the rapidly changing and often divergent regulatory landscapes of the European Union (EU)—with particular attention to Finland as a global sustainability leader—and the United States (U.S.). Multinational packaging producers face the ongoing challenge of harmonizing their sustainability activities and operations to meet varying legislative requirements across regions, including EU countries and U.S. states. At the same time, the literature remains quite short on comparisons between these markets despite an intensive flow of goods between these regions. Relying on qualitative interviews with practitioners and policymakers and building on the findings from the Package Heroes research project carried out in Finland, within the greater EU regulatory environment context, this chapter looks further at how packaging manufacturers headquartered in Finland navigate the regulatory environments of the EU and U.S. markets. This chapter further takes a stretch towards package manufacturers headquartered in the U.S. and exporting to or running their operations also in Europe, particularly in the EU. Despite our findings being hardly generalizable with a limited sample, we believe this chapter provides valuable input to the limited body of work overviewing the two Western contexts actively engaged in sustainable packaging developments.