Previous studies have shown that participation in social networking sites (SNSs) enhances users' knowledge, social capital, and quality of life. However, people with intellectual developmental disabilities (PIDD) do not use SNSs to the same extent as the general population does. This study aimed to explore the experiences of those PIDD in South Korea who use social media. Data were collected through face-to-face interviews with 20 PIDD. The study participants reported benefits associated with the use of SNSs, which included enhanced social capital, self-confidence, and positive self-image. Participants also used SNSs to maintain friendships, initiate new relationships, and engage in self and community advocacy. Safety concerns were also reported by the participants. The study concluded that SNSs can be used as tools for promoting community inclusion and developing social capital for PIDD. However, the outcomes of using SNSs depend on the availability of support provided by one's network. The absence of support may result in frustration and even exploitation. With effective support, SNSs become powerful tools that can be used by PIDD to combat social isolation through creating ample opportunities for social inclusion.