Responsible Investment is recognized as a critical part of the response to global environmental and social challenges. This paper examines the challenges and opportunities for Responsible Investment in emerging markets and developing economies that are urbanizing and showing rapid economic growth. The paper offers several considerable opportunities that could be tapped—a need for sustainable infrastructure and unmet markets. One key aspect is the role of public-private partnerships, which is important for leveraging resources and expertise. These partnerships, new financing mechanisms, and international support can help overcome the markets’ substantial barriers, such as weak regulation, underdeveloped financial ecosystems, and high perceived risk due to low access to capital. Seizing the opportunities can make emerging markets significant players in global sustainability initiatives.