Purpose: The purpose of this research is to develop a model of the impact of service quality, brand’s social identity and the attachment to the team on the loyalty of Iranian Premier League football team’s fans. Method: This is an applied study of descriptive-correlation type. The statistical population of this study consisted of the fans of the selected Iranian Premiere Football League. A probability clustering method was used for sampling. Azadi football stadium of Tehran, Imam Reza football stadium of Mashhad, Yadegar Imam Football stadium of Tabriz and Naghsh Jahan football stadium of Isfahan were selected and the questionnaires were distributed in the 12th week of the tournament (2018-2019 season) between fans in above named stadiums. 400 questionnaires were distributed equally in four stadiums and finally, 387 full questionnaires were received and this number was considered as a statistical sample of the research. A researcher-made service quality questionnaire, brand’s social identity questionnaire of Boyle and Magnusson (2007), fans’ attachment questionnaire of Yoon, Petrick, & Backman (2017) and fans’ loyalty questionnaire of Tachis and Tzetzis (2015) were used for gathering information. Structural equation model and LISREL software were used to review and test the hypotheses. Results: The result showed that brand’s social identity has a significant positive effect on the attachment and loyalty of fans (P˂ 0.05). The attachment of fans also has a significant positive effect on their loyalty (P˂ 0.05). Conclusions: It is concluded that for enhancing fan's loyalty, managers of football teams should notice to service quality as a key factor.