Nearly 15% of the global population, or one billion people, have some form of disability. However, direct discrimination on the basis of disability remains widespread, while people with disabilities experience among the highest rates of implicit bias. With the advent of the global disability rights movement and the adoption of the CRPD, the share of constitutions that explicitly guarantee equal rights on the basis of disability has grown, but many other constitutions use unexamined historical language that makes assumptions about capacity (e.g., provisions that limit civil and political rights based on “infirmity“ or “unsound mind“). These provisions, whether reflecting historic or persisting biases, have important implications for whether persons with disabilities can exercise the full range of fundamental rights. This paper will examine progress on disability rights in the constitutions of all 193 UN Member States over the past 50 years and assess what remains to be done.