Positive and strong relationships among various stakeholders are essential for the sustainable management of an organization. Despite growing interest in how various sport organizations manage stakeholders to promote social sustainability, there remains a gap in stakeholder and sustainability research in high school athletics. The purpose of this study was to examine how the social sustainability of sport organizations (i.e., high school athletics) were maintained during decision-making processes. Specifically, this study used a qualitative case study framed by stakeholder theory to investigate how the relevant decision-makers in high school athletics (i.e., principals and athletic directors) manage other stakeholders in their departmental decision-making processes to promote the sustainability of their athletic department. Two high schools from the US and South Korea, one from each country, were selected as the cases for the current study. Semi-structured interviews regarding stakeholder management in departmental decision-making processes were conducted with four individual interviewees, including the principals and athletic directors of each high school. The results of this study illustrated that both the US and the South Korean high school athletic departments utilized stakeholder engagement strategy in their departmental decision-making processes. The principals and athletic directors recognized the importance of communicating with other stakeholders and engaging them in athletic department decisions. Specifically, the organizational decisions of both high school athletic departments were made in consultation with the main internal stakeholders of the athletic department (i.e., the principal and athletic director) as well as other various stakeholders (e.g., parents, coaches, alumni association).