This article examines the role that the figure of the child has played in anti-gender arguments. Specifically, it focuses on the emergence of anti-gender protests and rhetoric in France around the 2013 gay marriage law, the mariage pour tous. I argue that “gender ideology” came to feature in French right-wing discourse during these gay marriage debates because of children. The bill mentioned neither gender nor children and yet most of the controversy centered on these two topics. My second argument is that the struggle around “gender ideology” in France was so heated because “gender” provided a framework to talk – and fight – about social cohesion, national sovereignty, reproduction, and cultural citizenship. “Gender” pointed to the possibility of cultural reproduction, as opposed to biologically-anchored procreation. In a time of growing anxieties around immigration and citizenship, “gender” appeared to open the door to homosexual parenting, to gender deviance, and to a radical redefinition of family, of the nation, and of the future.