In Australia, the state and territory governments are responsible for dealing with young people who are involved in crime. One major aspect of the juvenile justice system is the supervision of children and young people who have committed or are alleged to have committed an offence. This report presents information on the young people under juvenile justice supervision, both in detention and under community-based supervision, and the characteristics of their supervision. There are eight chapters in this report. Chapter 1 provides an overview of the report. Chapter 2 provides background information to the juvenile justice supervision system and the young people who are under juvenile justice supervision. Chapter 3 details the data and methods used in the report. Chapters 4 and 5 examine the characteristics of the young people under juvenile justice supervision and the supervision they experience. Chapter 6 contains further information on community-based supervision, while Chapter 7 focuses on detention. Chapter 8 summarises key information for each state and territory. Appended are: (1) State and territory juvenile justice systems, programs and services; and (2) Population data. (Contains 143 figures and 33 tables.) [Funding for this paper was provided by the Australasian Juvenile Justice Administrators.]