Research question: In this study we examine whether knowledge management (KM), along with innovation concepts (attitude toward innovation, open innovation, and innovativeness), evokes direct and indirect influences on organizational performance of nonprofit sports clubs. Research methods: A total of 266 valid questionnaires were collected online from board members of nonprofit sports clubs in Iran. Structural equation modeling was used to investigate the relationships between variables. Results and findings: The results indicate that KM has a positive effect on organizational performance via two different sequential mediators: attitude toward innovation and innovativeness, and open innovation and innovativeness. KM has a direct positive effect on sport clubs’ innovativeness and organizational performance. Implications: Nonprofit sports clubs should take advantage of promoting KM processes such as facilitating the development and sharing of new knowledge through relying on internal and external knowledge sources. By doing so, sports clubs can enhance capabilities to exploit external knowledge and foster a positive attitude towards newness and innovation which can help them to innovate more and perform better. The study provides theoretical and managerial implications that help sports clubs innovate and increase multiple aspects of their organizational performance.