The International Union for Pure and Applied Biophysics (IUPAB) is an international non-governmental organization whose mission is to assist in the worldwide development of biophysics, to foster international cooperation in biophysics, and to help in the application of biophysics toward solving problems of concern to all humanity. It was established in 1961 as the International Organisation for Pure and Applied Biophysics but then renamed as the International Union in 1966, when it became a member of ICSU, which itself was renamed in 2018 as ISC, the International Council for Science. Affiliated to it are the national adhering bodies of 61 countries, as well as the European Biophysical Societies' Association (EBSA), the Asian Biophysics Association and the Biophysical Society.