The Strategic Training in Transdisciplinary Radiation Science for the 21st Century (STARS21) training program is built on the foundation and legacy of the former Excellence in Radiation Research for the 21 Century Program (EIRR21). The Terry Fox Foundation, with matching support from the Princess Margaret Radiation Medicine Program and Princess Margaret Research, are funding a strategic training program for the next generation of trans-disciplinary health investigators. Our program has been designed to provide clinicians, graduate students and post-doctoral fellows with the skills essential to conducting innovative research in radiation medicine and with the leadership, management, collaboration and communication proficiencies necessary to define them as the future leaders of Canada's scientific community.