This study aimed to investigate the role of geography education and knowledge in enhancing spatial decision-making competencies in sustainable tourism planning and management. The study adopted a mixed-methods approach using a convergent quantitative–qualitative design. Quantitative data were collected through a Likert-scale questionnaire, and qualitative data were collected through semi-structured interviews with geography graduates who had participated in tourism planning and management projects. The accessible study population consisted of 120 individuals, of whom 75 were selected based on inclusion criteria. The results of Pearson correlation analysis indicated a positive and significant relationship between the level of geography education and managerial and spatial competencies in tourism (r = 0.63, p < 0.01). The results of multiple regression analysis also showed that geographic knowledge, work experience in tourism projects, and familiarity with GIS together explained 47% of the variance in tourism management skills (R² = 0.47). The qualitative findings further indicated that geographic knowledge contributes to improved decision-making in destination management by strengthening spatial analysis, route planning, identification of environmental capacities and constraints, tourist pressure management, and prediction of spatial visitation patterns. Given the correlational nature of the data and the partial reliance of the findings on respondents’ self-reports, generalization of the results requires caution and further studies using more objective data and broader samples. This research emphasizes the necessity of convergence among geography education, GIS skills, and tourism policymaking to enhance sustainable management of tourism destinations in Iran.