This paper uses pragmatic findings and lessons learned from three case studies to deduce that community-based rainwater harvesting (CB-RWH) is an innovative solution to develop sustainable drinking water supply systems in developing countries, especially in Africa and Asia. Taking advantage of traditional community-based activities in African and Asian villages, the water supply system can be significantly improved with the introduction and implementation of CB-RWH systems. Furthermore, sustainable, safe water sources in Africa and Asia can be brought to fruition when transparent self-regulatory management systems are supported through comprehensive design and maintenance guidelines and funded from private and public sources. To this end, the potential for CB-RWH to lead toward greater resilience and sustainability was investigated. Based on case studies of three successful demonstration projects in Africa and Asia, this paper identifies 14 innovative solutions resolving technical, economic, and social problems which have been barriers preventing the wide implementation of CB-RWH in developing countries, especially in Africa and Asia. It also recommends strategies to promote CB-RWH in African and Asian villages, which include the following: implementation of more pilot projects at local levels; promotion of and education in rainwater preservation and harvesting at all levels of the education system; and innovation in micro-funding systems in cooperation with corporate social responsibility activities. These strategies will promote the implementation of CB-RWH as a mainstream and high-priority technique for national, regional, and global water strategies.