Evolving National Identity in Korea (2012–2021) and Implications for Social Sustainability

National identity in Korea has undergone significant changes in recent years, reflecting broader shifts in social and political landscapes. Traditionally rooted in ethnocultural and ethnic frameworks, the concept of national identity is increasingly influenced by civic and pluralistic values, reflecting Korea’s growing diversity and globalization. This study aims to explore the transformation of national identity in Korea between 2012 and 2021 and its implications for social sustainability, with particular attention paid to Sustainable Development Goal 16. Using latent class analysis, this research examines survey data collected from Korean adults over the specified period. The analysis reveals a decline in ethnocultural and ethnic identities, with a corresponding rise in civic-oriented and flexible identity groups, such as Non-Territorial Ethnocultural Civic, Pluralistic, and Territorial-Cultural groups. These new categories illustrate a more complex understanding of national belonging, shaped by multiple dimensions. The results suggest that this evolving identity landscape promotes greater inclusivity and adaptability, crucial for fostering long-term social cohesion in a diverse society. The study highlights the need for policies, educational reforms, and media narratives that embrace this dynamic understanding of national identity. The findings offer important insights for policymakers and educators as Korea continues to navigate the challenges of diversity and globalization, ensuring a sustainable social future.