Grounded in multidisciplinary literature from public relations, sport communication, and marketing, this study examined consumer reactions to sustainability initiatives launched by major sports leagues. Through an online survey (N = 254), the results showed that sports league-cause fit resulted in more positive organization–public relationships (OPRs) such as through trust, commitment, satisfaction, and control mutuality. Further, the findings revealed that a closer geographic proximity of the sustainability initiative and an increased perceived impact (donation amount and number of beneficiaries affected) triggered higher perceptions of trust, organizational authenticity, and fandom toward the sponsoring sports league. Interestingly, a significant two-way interaction between spatial proximity and impact suggested that lower perceptions of the impact of the corporate social responsibility (CSR) program evoked more positive attitudes when involving local beneficiaries, whereas higher perceptions of impact improved organizational attitudes when the beneficiaries were located faraway. Lastly, the findings indicated that the OPR variables, especially trust, as well as fandom, and organizational authenticity elicited higher supportive intentions (e.g., support CSR cause, donate, volunteer, share on social media) toward the sports league. Theoretical implications for fit, construal level theory, and CSR impact as well as implications for sport communication practitioners are discussed.