What can the resettlement of North Korean defector-migrants into South Korean society today tell us about Korean national identity and the likely challenges of integrating the two Koreas tomorrow? In this paper, we report findings from a 2016 national identity survey of 334 North Korean defector-migrants currently residing in South Korea. It compares responses to that of native South Koreans and considers in-group differences of opinion. Overall, we find no substantive identity divergences between those from North Korea and native South Koreans. We do, however, find evidence of significant in-group identity differences, namely cohort effects. Older defector-migrants are more likely to see their “Koreaness” as defined by ethnocultural traits, feel closer to South Korea, and be more “patriotic” than younger migrants.