José Mariano Gago is an experimental high energy physicist and a Professor of Physics of at the Instituto Superior Técnico (IST) in Lisbon, Portugal. He graduated as an electrical engineer from the Technical University of Lisbon and obtained a Ph.D. in Physics from the École Polytechnique in Paris. He worked for many years as a researcher at the European Organisation for Nuclear Physics (CERN) in Geneva, Switzerland and in Portugal's Laboratory for Particle Physics (LIP), which he chaired. Gago is a member of the CERN Council. He chaired the High Level Group on Human Resources for Science and Technology in Europe.

As Minister of Science and Technology (S&T) during 1995-2002, Gago was responsible for science and technology and for information society policies. He launched the Ciencia Viva movement to promote S&T culture and S&T in society. During the Portuguese EU presidency (2000), he prepared, along with the European Commission, the Lisbon Strategy for the European Research Area and for the Information Society in Europe. In 1998 he also launched the Eureka-Asia Initiative in Macao. During the 2007 Portuguese EU Presidency he promoted the adoption of a strategy for the future of S&T in Europe and for the modernization of universities in the EU.

Gago was President of the International Risk Governance Council (IRGC) in Geneva and is a member of IRGC Board. He is a member of the Academia Europaea.