This chapter discusses the issue of whether the 21st century will be an “Asian Century.” According to a study commissioned by the Asian Development Bank, Asia 2050: Realizing the Asian Century, Asian countries will keep growing and eventually account for more than half of global GDP by 2050. The study, however, cautions that developing Asia may fall into the “middle-income trap” where growth stagnates due to the lack of productivity growth. This chapter provides baseline projections for the world economy up to 2050 and argues that the “Asian Century” scenario may be interpreted as one of the high growth cases for the model, and Asia may face the risk of stagnation due to the middle-income trap and/or “Asian conflict” resulting from political, security, and military tensions in Asia. The chapter argues that in order to realise an “Asian Century,” developing Asia needs to focus on technological progress, inclusive growth, environmental sustainability, institutional and governance quality, and regional cooperation and integration. It also points to possible global governance structures which are alternatives to an Asia-centric world, such as those of a “China Century,” “American Century 2.0,” “G-2,” “G-0,” and a “multi-polar” world. As the two major powers in this region, China and Japan need to cooperate with each other to maintain regional peace and security, and help realise the “Asian Century.” The chapter concludes that even when the “Asian Century” arrives and Asia dominates the world in terms of economic size, it does not necessarily mean that Asia will dominate the world politically, institutionally, militarily, or in soft power. The 21st century will likely be a “multi-polar” world where the traditional powers of the West (the United States and European Union countries), Japan, and new rising powers (China, India, and other major emerging economies) collectively manage global economic and political affairs.