To describe time use clusters and correlate-cluster profiles of Australian youth.Secondary analysis of cross-sectional national survey.Data were from the National Children's Nutrition and Physical Activity Survey, a random sample (n=1853) of 9-16 years old Australians (February-August 2007). Time use data were collected using the Multimedia Activity Recall for Children and Adults, and collapsed into 17 age-adjusted variables for sex-specific cluster analysis. Cluster associations with socio-demographic, anthropometric, health and dietary variables were analysed.For boys (n=930), the Social tasker cluster was characterised by social interaction and chores & work, the Techno-active cluster by team sport and TV and the Techno-studious cluster by video games and study. Average daily pedometer steps, age and remoteness were significant cluster correlates. For the girls (n=923), the Social screenie cluster was characterised by TV and social interaction, the Quiet actives cluster by quiet time and non-team sport and the Techno-studious cluster by video games and study. Pedometer steps, age, parental income and education, parent-child age difference, "extra foods", fat and fruit intakes were significant correlates.Distinct sex-specific time use clusters and profiles exist among Australian youth. These findings may assist the development of targeted time use interventions to improve health and well-being.