This chapter explains the role of the principle of consent in maternity care, including its philosophical and moral basis in human autonomy and its protection in the English legal system. It introduces the philosophical rationale behind the principle of consent, its manifestation in the legal system and suggests a more sophisticated way of conceptualising consent as a positive right to evidence-based care and choice in healthcare. The principle of consent is widely overlooked in maternity care in which woman are frequently subject to routine procedures, such as antenatal screening, vaginal examinations, amniotomy and electronic fetal monitoring, based on hospital policies that sideline the need for individuals to give their consent. Informed consent is an essential component of the broader principle of respectful care, namely care that respects a person's human dignity, which encompasses their right to humane treatment and treatment that promotes their autonomy. The chapter also explains the pre-eminent place of consent in medical ethics and the law.