Background: It is evident that people with disabilities worldwide face digital divide; although this divide has been mitigated owing to greater access to technologies, a gap remains in terms of Internet use. Given that South Korea has one of the highest Internet access rates, it is necessary to examine how adults with intellectual and developmental disabilities (IDD) access the Internet, and what correlates with Internet usage. Method: A total of 298 adults with IDD in South Korea participated in the survey. Results: The participants reported benefits from the Internet including increased opportunities for leisure and entertainment, updated news and networking with friends. Internet access was found to be pervasive among people of younger ages and less severe disabilities. Further, Internet usage corresponded to material access, digital literacy and a positive attitude towards digital applications. Conclusions: Targeted digital literacy programmes can be developed for adults with IDD.