Effective city branding necessitates the identification and enhancement of the city's competitive advantages to create a coherent and appealing image of its urban identity in the minds of both domestic and international audiences. The present study aims to analyze the factors and core capabilities that create the competitiveness of the urban brand for the port city of Mahshahr. This research is applied in purpose and descriptive-analytical in its execution method. It is based on the perspectives of 25 key experts and stakeholders in the field of study, including: academic specialists (professors of Geography and Urban Planning from Shahid Chamran University of Ahvaz and Islamic Azad University, Mahshahr Branch) and officials of Mahshahr's urban management (Municipality, City Council, and Governorate of Mahshahr), as well as organizations related to tourism, industry, mining and trade, ports and maritime affairs of Mahshahr, and the Imam Khomeini (RA) Petrochemical Special Economic Zone. The data collection tool was a researcher-made questionnaire, whose content validity was confirmed, and its reliability was calculated and verified using Cronbach's alpha coefficient of 0.956. To analyze the collected data, using the Fuzzy Delphi Method, the core capacities for urban brand competitiveness were identified and prioritized across 6 dimensions and 47 factors. The research findings indicated that, from the experts' perspective, natural and environmental indicators (0.728) and economic indicators (0.614) were identified as the most important core capabilities for urban brand competitiveness, respectively; in contrast, the historical indicator, with a value of (0.103), is considered the least important dimension in this context.