In this study, we systematically examine the relevance of five bodies of social movement theory to the outcomes of two sport-related social movements — struggles over funding of sport facilities and struggles over Native American mascots. Thirty-eight themes were culled from the five bodies of social movement theory and explored via 83 semi-structured interviews with social movement and countermovement actors from 20 different sites in the United States. Surprisingly, we found only eight of the 38 themes that we studied are pivotal to the outcomes of both social movements. The analysis also reveals that no single theoretical approach adequately explains the outcomes of both movements. Parts of Resource Mobilization theory are useful, while Political Process and Cultural theories offer the most explanatory power. We find that a few internal aspects of social movement groups interact with some cultural and structural forces external to these groups to shape social movement outcomes. Sport sociologists are urged to continue the systematic study of social movement theory, but to move beyond the limitations of this study to focus on other social movements, geographical locations, and aspects of social movements.