Daily links between alcohol use and sexual behaviors were examined in a longitudinal study of college students. Hierarchical linear models predicted sexual behaviors by characteristics of persons (N = 731, Level 3), semesters (N = 4,345, Level 2), and days (N = 56,372, Level 1). On a given day, consuming more drinks and binge drinking were associated with greater odds of kissing, touching, oral sex, and penetrative sex. Consistent with alcohol myopia and expectancy theories, associations between binge drinking and sexual behaviors were stronger for students not in romantic relationships, for students with stronger alcohol-sex expectancies, and for oral and penetrative sex. Findings suggest that within-day links between alcohol use and sexual behaviors are evident across college, with variations based on individual and relationship factors.