Objective This study aimed to investigate the facilitators and barriers to adopting an active lifestyle among post-treatment cancer survivors in France. Methods Breast, colorectal, lung, and prostate cancer survivors were recruited. Participants completed a questionnaire covering sociodemographic and clinical factors, physical activity (PA) experiences, variables from the Transtheoretical model, types of motivation, knowledge of PA benefits, barriers to PA, and quality of life. We categorized participants into 4 profiles combining PA level and sedentary behaviors. Results One hundred and seventy-five participants were included. Ordinal logistic regression revealed that the active lifestyle of cancer survivors is influenced by their professional situation (OR, 3.99; 95%CI, 1.76-9.10 and OR, 3.14; 95%CI, 1.45-6.77), the use of self-liberation (OR, 0.41; 95%CI, 0.20-0.82), helping relationships processes of change (OR, 2.45; 95%CI, 1.20-5.00), and quality of life (OR, 1.11; 95%CI, 1.04-1.18). Conclusions Identifying the factors associated with PA and sedentary behavior among cancer survivors in France will facilitate the adaptation of programs according to a whole-person approach. Semi-structured interviews will further enhance insights in this mixed-methods study. Practice implications Interventions aimed at promoting an active lifestyle among cancer survivors should be customized based on professional situation, the utilization of experiential behavior change processes, and perceived quality of life.