Objective: The aim of this study was to examine the associations between physical activity (PA) and subjective well-being (SWB) by focusing on the intensity of PA and different components of SWB. Participants: The sample included 723 undergraduate students (mean age = 19.3 years). Methods: Participants responded to questionnaires measuring life satisfaction, happiness, positive affect, negative affect, vigorous-intensity PA, moderate-intensity PA, and walking. Multiple regression models were performed with the SWB variables as the outcomes and PA variables as the predictors while controlling for age and sex. Results: While vigorous-intensity PA was the only significant predictor for life satisfaction, both moderate-intensity PA and vigorous-intensity PA were positively associated with happiness and positive affect and negatively associated with negative affect. Walking was not associated with any component of SWB. Conclusion: PA has a positive relationship with SWB in college students and this relationship differs by the intensity of PA and the component of SWB.