The 12th ITER International School will be hosted by Aix-Marseille University in Marseille. The subject of this year’s school is “The Impact and Consequences of Energetic Particles on Fusion Plasmas”. As the start of ITER operations approaches, it is timely to address this multidisciplinary topic that includes plasma self-heating by fusion-born alpha-particles, the influence of energetic particles on stability, diagnosing energetic particle transport and loss, and understanding runaway electrons. The ITER International School aims to prepare young scientists and engineers for working in the field of nuclear fusion and in research applications associated with the ITER Project. The adoption of a “school format” was a consequence of the need to prepare future scientists and engineers on a range of different subjects and to provide them with a wide overview of the interdisciplinary skills required by the ITER project.