Taiwan began to systematically introduce social innovation as a tool for social reform after the 2008 financial crisis. Although most research on social innovation in Taiwan focuses on problem-solving methods based on the utilitarian perspectives of the public and private sectors, an analytical framework from the societal perspective is proposed in this article. We classify social innovation conducted by the public, private, and civil society sectors as either incremental or radical. This article seeks to provide an overview of the development of social innovation in Taiwan and to answer two main questions. First, how do Taiwan’s government and the private sector mainstream incremental social innovation, and what is its influence? Second, how does a radical approach emerge under this influence? This article illustrates how political and social contexts shape the development of social innovation and uses deliberative democracy in practice as a case study to show how radical social innovation emerges and develops.