This chapter aims to synthesize historical and contemporary literature to provide an overarching understanding of social-emotional competence in individuals with Down syndrome, where social-emotional competence refers to the skills necessary to allow for successful social relationships, as well as the ability to regulate the experience and expression of emotions. Using the framework of Rose-Krasnor’s prism model, this chapter addresses each of the four components that underlie the development of social-emotional competence: self-regulation, social awareness, prosocial orientation, and social problem-solving. The development of each of these components is described for individuals with Down syndrome, and a description of the typical developmental trajectory is given for reference. The short-term and long-term implications of each component are also discussed, as they relate to the individual’s overall social-emotional competence. This overview aims to highlight what is known regarding social-emotional competence in individuals with Down syndrome, as well as to identify areas in which knowledge is lacking.