Purpose: Whole-of-school approaches to physical activity (PA) promotion are recommended internationally, but there remains little descriptive research detailing the implementation of such approaches, especially at the secondary level. The purpose of this case study, which drew upon a social-ecological perspective, was to examine a whole-of-school approach used by one secondary school in England. Method: Participants (N = 30) included three members of the school's senior leadership team, eight teachers, 15 students, and four parents. Data were collected during 5 months using open-ended questionnaires that all participants completed, 14 staff interviews with staff, three focus groups with students, six observations, and attendance records from various PA opportunities. Results: Thematic analysis identified five key PA opportunities and uncovered four themes in relation to these opportunities--Student Autonomy, Support from Leadership, New School, and Physical Education Time. Discussion/Conclusion: This study highlights the importance of targeting multiple levels of influence when implementing whole-of-school PA programming.