The purpose of this research was to investigate the relationship between social media marketing and repeat purchase intention with the mediating role of customer value co-creation in Tehran sports clubs. The present study was applied research in terms of objective and descriptive-correlational in terms of data collection, conducted using the field method. The statistical population of this research included all customers of sports clubs in Tehran, and considering the extensive statistical population and the unknown number of them, 384 individuals were selected as the research sample based on the Morgan table for an unlimited population. The sampling method was multi-stage cluster random sampling. To collect research data, the questionnaires of Baek et al. (2010) for repeat purchase intention, Thulasiram and Varsha (2011) for social media marketing, and Shamim et al. (2009) for customer value co-creation were used. The research data were analyzed using structural equation modeling. The results of the study showed that social media marketing has a positive and significant effect on customer value co-creation and repeat purchase intention of sports club customers. Moreover, customer value co-creation has a direct and significant positive effect on repeat purchase intention of sports club customers. Additionally, customer value co-creation played a partial mediating role in the relationship between social media marketing and repeat purchase intention of Tehran sports club customers. According to the study results, it is evident that the use of social media marketing can significantly influence the improvement of customer relationships and value creation in sports clubs. Considering the important role of customer value co-creation in the relationship between social media marketing and repeat purchase intention, Tehran sports clubs can focus on more effective utilization of these two elements to enhance customer satisfaction and performance. As a suggestion, sports clubs can improve their marketing programs based on data collected from social media and provide engaging and diverse content to create value for customers. Moreover, developing strategies to increase interaction with customers and establish bilateral relationships between the club and customers can also help increase their repeat purchase intention. Overall, this research demonstrates that the use of social media as a tool for marketing and customer relationship management can lead to improved performance and increased sales for sports clubs.