Health is the primary focus of Alcott’s novel Eight Cousins (1875), whose narrative is structured around the protagonist’s journey from ill-health to wellness. By placing Eight Cousins in conversation with contemporaneous health advice for girls, this essay advances that Eight Cousins manifests the ideology of hygiene. As one of the first writers to target a juvenile female audience, Alcott’s work helped to popularize the concept of hygienic health for girls. Eight Cousins fuses the bildungsroman and wellness-narrative genres to formulate a version of girlhood in which engaging in hygienic behaviors forms a critical component of girls’ healthy self-development, aligning the achievement of health with attaining personal agency. Alcott’s investment in hygienic health for girls stems from her belief in the importance of self-governance as a form of feminine agency. In enacting the principles of girls’ hygienic health, especially the emphasis on individual agency, Eight Cousins provided girl readers with a model for maturation that enabled them to achieve health as well as agency within the domestic sphere.