Thirty years ago, the transgender child would have made no sense to the general public, nor to young people. Today, children and adolescents declare themselves transgender, the National Health Service diagnoses 'gender dysphoria', and laws and policy are developed which uphold young people's 'choice' to transition and to authorize stages at which medical intervention is permissible and desirable. The figure of the 'transgender child' presumed by medicine and law is not a naturally occurring category of person external to medical diagnosis and legal protection. Medicine and law construct the 'transgender child' rather than that the 'transgender child' exists independently of medico-legal discourse. The ethical issue of whether the child and young person can 'consent' to social and medical transition goes beyond legal assessment of whether a person under16 years has the mental capacity to consent, understand to what s/he is consenting, and can express independent wishes. It shifts to examination of the recent making of 'the transgender child' through the complex of power/knowledge/ethics of medicine and the law of which the child can have no knowledge but within which its own desires are both constrained and incited.