Over the past few decades, South Korea has experienced economic development and urbanisation, the effects of which have included environmental degradation and social problems. The principles of sustainable development have gained support as an approach to dealing with these issues; and the compact city has been proposed as a means of delivering sustainable development without the sprawl of Western cities. This thesis examines the applicability of the compact city to South Korea, particularly to large-scale developments, through the perspective of sustainable development. The research questions, ‘How and why have urban developments in South Korea been accompanied by compactness?’ and, ‘What implications does this have for sustainable development?’ are examined through two case studies: Yong-in, a city developed by diverse methods; and Se-jong, a city developed as a single new project. The case studies demonstrate that new settlements by high-rise apartments in South Korea have achieved a high degree of compactness, and residents have appreciated their liveability and made them their popular housing choice. The thesis concludes that the compact city in South Korean urban development is not only feasible, but is acceptable to residents; and it suggests a compact city model and strategies applicable in the South Korean context.