Over the last two decades East Asian countries have demonstrated the simultaneous developments of state welfare provision, immigration control and immigrant integration policy. Despite significant growth in related interest and research, studies on immigrants and their social inclusion are still relatively scarce, especially in terms of the intersection of East Asian welfare and immigration regimes. This study thus examined and compared, from a historical perspective, the development of welfare and immigration regimes and their impact on the social rights of low‐skilled labour migrants in Japan and South Korea. These two countries have taken somewhat divergent paths, which has resulted in the persistent ethnic differentiation of low‐skilled labour migrants in Japan and their ethnically hierarchical inclusion in Korea. This article argues that the two policy legacies of East Asian welfare and immigration regimes, namely, productivism and ethnic nationalism, still significantly matter in policy making related to low‐skilled labour migrants.