This study developed an impact investing ecosystem framework to present a comprehensive overview of the impact investing sector, identifying key challenges and possibilities. Two Asian countries, Japan and Singapore, were used as case studies. The proposed framework revealed that the market scales in Japan and Singapore were small and each country faces unique challenges for developing impact investing. For Japan, the low level of philanthropic activities and the small social sector were the key challenges to overcome for impact investing growth. For Singapore, the government’s low social expending strategy may limit the development. However, both countries have supportive environments for impact investing due to high-quality human resources, well-developed financial markets and political interest. In particular, the high total wealth of high network individuals (HNWI) in Japan and large donations to charities in Singapore (% GDP) offer rich potential.