This project investigated the relationships between exercise motivation, athletic identity, exercise frequency and subjective well-being by drawing on concepts from Self-Determination Theory and athletic identity research. The conceptual framework underlying the research suggested that athletic identity would provide a link between exercise motivation and exercise frequency and subjective well-being. Four hundred participants completed exercise motivation, athletic identity, exercise frequency, and well-being measures. Both higher external and intrinsic exercise motivation were associated with a higher level o f total athletic identity and greater frequency o f exercise. Higher intrinsic exercise motivation was associated with more positive affect and life satisfaction and higher external exercise motivation was associated with more negative affect. Total athletic identity, self-referent athletic identity and social-referent athletic identity mediated the relationships between exercise motivation, exercise frequency and well-being. These results support conceptual links between exercise motivation, athletic identity and well-being and lay the foundation for future research.