This chapter focuses on the role of nationality laws in relation to marriage migration to South Korea (‘the Republic of Korea’ or ‘Korea’) and Taiwan (‘the Republic of China’) in manufacturing gendered nationality and statelessness. It illustrates how gender-based statelessness serves the interests of the ‘nation-state’ by excluding some female marriage migrants from membership of the nation. This is because nationality laws confer a status on those marriage migrants who advance the project of nation building by reversing falling birth rates. It argues that discriminatory nationality laws in Korea and Taiwan reflect traditional East Asian framings of nationality based on cultural and ethnic patriarchal lineage. The chapter demonstrates how laws and policies on nationality, in both Korea and Taiwan, both include and exclude the marriage migrant on the basis of gender, nationality, race, class, culture and ethnicity; it thereby exposes the causes of statelessness in the context of marriage migration. The chapter applies a construction of gender as based on power relations involving the state, social structures and individuals in the context of nationality laws in Korea and Taiwan.