Objectives: First generation students transitioning to college experience specific challenges that impact on their engagement in physical activity. Furthermore, this population experiences a context disruption that provides a unique opportunity to examine whether intention and habit predict physical activity. The aim of the current research was to determine the efficacy of the theory of planned behavior in the prediction of intention and behavior within this population, and to determine whether habit contributes to the prediction of physical activity. Methods: In this observational study, a convenience sample of first generation college students (N = 101) completed measures of theory of planned behavior variables and habit strength at Time 1, and one week later reported physical activity. Results: The theory of planned behavior was partially supported in this context, as intention was the only significant predictor of behavior. Habit strength accounted for additional variance in physical activity but did not moderate the relationship between intention and behavior. The hypothesized model accounted for 46.9% of the variance in physical activity, and intention (β = .455) and habit (β = .364) were significant predictors. Conclusions: Intention and habit exert independent effects on physical activity within this population, and are both suitable targets for intervention.