Objective: To investigate separate and combined associations of occupational social class and personality traits with late midlife leisure-time physical activity duration and intensity. Method: Cross-sectional data from the Copenhagen Aging and Midlife Biobank (N = 4,649) were analyzed using linear regression models with leisure-time physical activity (metric equivalence) as outcome. Results: Low versus high occupational social class was associated with 4% (95% confidence interval [CI] = [3%, 5%]) greater leisure-time physical activity duration, but 2% (CI = [1%, 3%]) lower intensity. Each 10-unit increase in extraversion was associated with 5% (CI = [2%, 8%]) greater duration. Intensity increased by each 10-unit increase in conscientiousness (6%, CI = [4%, 7%]), openness (3%, CI = [1%, 4%]), neuroticism (3%, CI = [1%, 4%]), and extraversion (5%, CI = [4%, 7%]). Conscientiousness was positively associated with duration in low, but not in high, occupational social class (interaction p value = .002). Discussion: Higher occupational social class was associated with lower leisure-time physical activity duration, but higher intensity. Extraversion was positively associated with duration and intensity. Conscientiousness, openness, and neuroticism were positively associated with intensity. Overall, interactions were not consistent.