This report presents information on the youth detention population in Australia, focusing on quarterly trends from June 2009 to June 2013. On an average night, there were about 1,000 young people in detention, about half of whom were unsentenced. Numbers and rates of young people in detention remained relatively stable over the 4 years nationally; however, this trend varied between different states and territories. Around half of all young people in detention on an average night were Indigenous.