This chapter provides an overview of German laws that are particularly relevant to the rights of people with mental disorders. While its focus is on guardianship law, the chapter also briefly discusses Mental Health Assistance Laws, the implications of the United Nations Convention of the Rights of Persons with Disabilities, and the Patients’ Rights Law. Key elements of German guardianship law include respect for autonomy, a prioritisation of supported over substitute decision-making, a prioritisation of the person’s will and preferences over objective categories of well-being, and protection of the deeply held will and preferences of individuals who lack mental capacity and pose a considerable risk of harm to themselves. The primary task of the guardian is to support the person concerned in managing their own legal affairs. Only if the provision of adequate support does not enable the person concerned to make decisions based on their own will and preferences, the guardian can act on their behalf. Substitute decisions made by a guardian must be consistent with the deeply held values and preferences of the person concerned, as derived from the person’s advance directive, preferences they expressed previously, or the person’s ‘presumed will’. Various actions of the guardian are subject to court approval, including financial investments, security deposits, high-stake medical decisions and involuntary interventions. A central element in the court proceedings is an in-person hearing of the person concerned. Involuntary interventions are additionally subject to strict conditions of proportionality. Keywords