Daily covariation of sleep quantity and quality with affective, stressful, academic, and social experiences were observed in a sample of Canadian 17-19-year-olds in their first year of university. Participants (N = 191) completed web-based checklists for 14 consecutive days during their first semester. Multilevel models predicting sleep quantity and quality from daily experiences indicated that more time on schoolwork, expecting a test, and alcohol use predicted less sleep whereas socializing predicted more sleep. More positive affect and no alcohol use predicted better sleep quality. Models predicting daily experiences from sleep the night before indicated that less sleep preceded increases in negative affect, decreases in schoolwork time, and a higher likelihood of socializing. Better sleep quality preceded increased positive affect, decreased negative affect and stress, and less time on schoolwork. These data are informative for understanding relations between sleep and daily experiences as they occur naturally in first-year university students.