Airports are strategic enablers for city-region economies, with their growth and global emergence being mutually dependent. Despite their interdependence, growth strategies, and objectives can vary, potentially hindering the effective exploitation of global opportunities for mutual benefits. This paper analyses the symbiotic relationships between airports and city regions, as integral parts of business ecosystems and how they can contribute for the development of emerging global city regions and assist professionals and stakeholders to capitalise on global opportunities more effectively. Guided by a pragmatic paradigm and employing a case study approach, this multi-disciplinary paper explores the symbiotic relationships between airports and city regions in Southeast Queensland, Australia, in the context of a business ecosystem under the lens of Complexity theory focusing on six global city attributes: Connectedness, Networks, Governance/Management, Size/Scale, Informational Technology, and Migration/Tourism. The results are then compared across large, medium, and small city regions and their respective airports, providing findings on the symbiotic relationships and highlighting the potential for future research on emerging global city regions.