Physical activity is safe and beneficial for children, adolescents, and young adults diagnosed with cancer. However, few physical activity programs are available for young people diagnosed with cancer. This is partly because cancer is rare in young people, and so it is hard to create programs that can be accessed by everyone. In my research, I create and test physical activity programs that consider the needs of young people diagnosed with cancer. Over the next 5 years, I will work with children, adolescents, and young adults diagnosed with cancer and their parents, cancer support organizations, fitness professionals, healthcare providers, and researchers to create online physical activity programs that are safe and accessible. I will then implement and test these physical activity programs with young people diagnosed with cancer across Canada. My work will lead to new physical activity opportunities with the potential to improve the health of young people diagnosed with cancer across the country.