Leisure activities engagement could promote freshmen's well-being by providing social support and improving positive mood. Little is known about the day-to-day variability in leisure activities and stress and their links to daily well-being. Using a month-long daily diary design among 273 Canadian freshmen (M[subscript age] = 18, 73% female, 32% White), this study investigated the relations between daily leisure activities, stress, and well-being. Multilevel modeling revealed that daily leisure activities showed concurrent positive effects on daily well-being, whereas daily stress had negative effects. There were substantial inter-individual differences in these links, which were partly explained by coping orientations and person-average levels of stress. Engaging in more diverse leisure activities was related to better well-being. The findings demonstrate the immediate beneficial effects of leisure activities on well-being in everyday life and provide interventions with amendable targets to promote freshmen's positive socioemotional development during their transition to university.