Individual and household-level characteristics that influence sexual behavior have been extensively studied in South Africa, but community characteristics have received limited attention. We use multilevel discrete time hazard models and multilevel logistic regression models to analyze data from a representative sample of young people in KwaZulu Natal, and from several sources of community data. Results suggest that, net of individual and household characteristics, higher levels of community concentrated disadvantage are associated with increased hazard of sexual initiation and higher risk of unprotected sex. Social disorder increases the hazard of sexual initiation, while greater community social cohesion is associated with delayed sexual debut, although the latter association appears stronger for young men than for young women. We discuss these results and the ways they vary from predictions based on US. theory in light of conditions prevailing in contemporary South Africa.