© American Marketing Association 2018. Globalization and technology have expanded the reach of sports teams, giving brand sponsors new opportunities to engage and build relationships in real time with fans outside a team’s home market. This research investigates the role of fan isolation, or the experience of feeling separated from the team community, in shaping sponsorship effectiveness. The authors posit that such isolation increases the desire to affiliate with the team community, which can increase preferences for team-linked brands. However, the effect of isolation on sponsor performance depends on the strength of fan identification. Isolation increases strong fans’ desire to affiliate with the team community, thereby enhancing sponsorship performance; by contrast, isolation causes weak fans to avoid team-linked brands. Two field studies and four quasi experiments conducted across three countries (N = 1,412) confirm these predictions. Isolated strong fans exhibit increased recall, attitudes, purchase intentions, and word of mouth for sponsors, while isolated weak fans display the opposite effects. For brand managers, the proposed framework reveals whether isolated fans provide the best or worst returns on their sponsorships.