This qualitative study employed thematic analysis to identify factors influencing Iran's sports diaspora. Participants were 19 Iranian migrant athletes, coaches, referees, and sport administrators, selected via purposive snowball sampling. Data were gathered through in-depth semi-structured interviews until theoretical saturation and analyzed using Braun and Clarke's six-phase framework across three levels: initial codes, sub-themes, and main themes. Trustworthiness was established through Lincoln and Guba's criteria (credibility, transferability, dependability, and confirmability), with test-retest reliability yielding an agreement coefficient of 0.82. The analysis revealed 92 initial codes, 23 sub-themes, and 6 main themes: (1) individual and motivational factors shaping diaspora formation and continuity; (2) structural and institutional factors determining engagement with the diaspora; (3) socio-cultural factors underpinning diaspora; (4) economic-professional factors sustaining diaspora; (5) transnational and network factors—the core of the diaspora; and (6) barriers and challenges to leveraging diaspora capacities. The transnational and network dimension had the highest frequency (21 themes, 22.8%), underscoring the pivotal role of diaspora networks, transnational identity, and communication technologies in shaping this phenomenon. The findings suggest that Iran's sports diaspora is a multifaceted and complex phenomenon that, through strategic governance, reframing it from a challenge to an opportunity, and removing legal and cultural obstacles, can serve as a strategic asset for the sustainable development of Iranian sport.