The purpose of this study was to design and analyze a model of sports diplomacy to promote Iran’s national interests in the process of sending athletes to the Olympic Games. This qualitative research was conducted using the grounded theory approach, employing semi-structured interviews with 12 experts in sports policy, management, and international relations, selected through purposive sampling. Data analysis was performed in three stages—open coding, axial coding, and selective coding—using MAXQDA 2022 software. In total, 57 initial codes, 12 sub-themes, and 6 main themes were extracted. The main themes included “Policy-Making and Formal Interactions,” “Cultural Relations and Public Diplomacy,” “Media Utilization and Public Opinion,” “Capacity Building and Human Resources Development,” “Empowerment of Athletes,” and “Development of International Networking.” Findings indicated that promoting Iran’s national interests at the Olympics requires a comprehensive and integrated approach, combining political, cultural, media, economic diplomacy, and strengthening international networks. The proposed model emphasizes the necessity of intersectoral collaboration, development of soft and communication skills among athletes and managers, strategic media utilization, and building sustainable international networks. Accordingly, it is recommended that sports policymakers in Iran prioritize the advancement of sports diplomacy as an effective tool for enhancing the country’s international status, national branding, and for facilitating economic and social benefits.