Research over the past fifty years has shown weight stigma to be a pervasive form of social prejudice that is found in nearly every aspect of children’s lives – in school, peer relations, the media, even their own homes – and yet weight stigma is often not recognized as a social justice issue for children. This chapter explores the prevalence and presentation of weight bias in youth and the consequences of growing up in an environment that does not recognize body diversity as a natural part of human diversity. Evidence suggests that being the target of weight-based prejudice and discrimination has serious and long-lasting consequences for children’s physical, social, and emotional health and well-being. While higher-weight children and adolescents undeniably bear the brunt of societal weight stigma, youth across the weight spectrum are negatively affected by a culture that idealizes thinness and condemns fatness. The prevalence of body image and eating concerns, weight-related teasing, and bullying among youth underscores the need for sociocultural change in values and views around body size. This chapter considers important intersections of weight, health, and social justice in youth, and concludes with a case example of structural efforts to promote body respect and equality.