In the United States, there are more than 14 million cancer survivors. Many of these survivors have been treated with multimodal therapy including surgery, radiation therapy, chemotherapy, and targeted therapies. These therapies improve survival; however, they also cause acute and chronic side effects that can undermine health and quality of life. Physical activity (PA) and cancer survivorship is a rapidly growing field of inquiry that studies the role of PA in people diagnosed with cancer. In this article, we propose the following top 10 research questions for the field of PA and cancer survivorship: (1) Does PA reduce the risk for cancer recurrence and/or improve survival? (2) Does PA influence cancer treatment decisions, completion rates, and/or response? (3) What is the optimal PA prescription for cancer survivors? (4) What is the role of sedentary behavior in cancer survivorship? (5) What are the most effective PA behavior change interventions for cancer survivors? (6) Which cancer variables modify the PA response? (7) What are the safety issues concerning PA in cancer survivors? (8) Which specific cancer symptoms can be managed by PA? (9) Is there a role for PA in advanced cancer? And (10) How do we translate PA research into clinical and community oncology practice? The answers to these questions are critical not only for advancing the field of PA and cancer survivorship, but for improving the lives of the millions of cancer survivors every year who are diagnosed with cancer, going through treatments, recovering after treatments, or coping with advanced disease.