This chapter proposes a human security framework – based on the axis of freedom from fear, from want and to live with dignity – that emphasises the widespread risks to individual human rights violations, as a more complete and integrated approach for women’s engagement with international law. Despite the potential of the human security–human rights link as a reciprocal symbiosis, while most human security ideas have been related to human rights at the general or discursive level, they have not connected at a deeper juncture. A gendered and human rights-based approach to human security in international law would bear fruitful results, but has seldom been explored. Thus, this chapter will focus on human security and its core human rights content, and explain why this development/reconceptualisation is important for women and girls, in particular what problems it may address and what objectives it may achieve; and, secondly, what a feminist human security–human rights lens means for the future of feminist engagement with international law at the international, regional and national levels. It will do so especially through the illustrative case study of female undocumented migrants. Indeed, undocumented migrant women and girls are some of the most vulnerable persons in the world today. They face cumulative and intersectional forms of violence, deprivation and human rights violations. However, feminist approaches to international law have not fully engaged with this reality. The chapter will thus use this case study to spell out more general implications of the feminist human security–human rights approach for women’s involvement with international law in the twenty-first century.