Cities find internationalization not only as an opportunity but as a necessity for their survival in global competitive environments. This study identifies stakeholder participation as a critical element in co-creating a city brand, recognizing the importance of their involvement in the branding process. Implementing a qualitative design, including discussion groups and semi-structured interviews, this research captured the perspectives of stakeholders in Medellín, exploring foundational pillars for the city competitiveness. As a result of this research, a novel model is presented for internationalization of cities, incorporating stakeholder perspectives that highlighted key areas such as tourism, exports, cooperation, talent attraction, and foreign direct investment. Our findings offer new insights into the role of stakeholder participation in city branding and competitiveness on a global scale, revealing an optimistic outlook, emphasizing innovation, and public–private partnerships as crucial drivers. The study identifies strengths and challenges, providing insights for developing effective internationalization strategies.