Physical activity confers many physical and psychosocial benefits for adolescent and young adult cancer survivors, yet most are not active enough to accrue benefits. Parental support for physical activity may be important to consider when exploring factors that influence physical activity in this population. Explore adolescent and young adult cancer survivors' experiences of parental support for physical activity received and their parents' experiences of support provided. Ten adolescent and young adult cancer survivors ( = 17.4 ± 3.2 years; 70% male) and one of their parents (50% fathers) were interviewed separately. Data were analyzed thematically. Participants' experiences were summarized into three main themes: (1) , (2, and (3) . In general, there was congruence between participants' perceptions of the types of support provided and received for physical activity. However, parents felt their role was to provide instrumental, informational, and emotional support, whereas adolescent and young adult cancer survivors emphasized the importance of companionship support. Findings underscore the complexity of parental support for physical activity among adolescent and young adult cancer survivors. Developing and testing resources to empower adolescent and young adult cancer survivors to ask for parental support and to enable parents to support their child's physical activity is imperative.Implications for RehabilitationMany adolescent and young adult cancer survivors do not participate in enough physical activity to acquire physical and psychosocial benefits.Parental support may represent a key factor that influences physical activity participation.Rehabilitation professionals should consider the influence parents may have on adolescent and young adult cancer survivors' physical well-being post-diagnosis.Promoting co-participation may be a viable strategy to enhance physical activity participation among adolescent and young adult cancer survivors.