Juvenile delinquency, also known as juvenile offending, is the act of participating in unlawful behavior as a minor or individual younger than the statutory age of majority. These acts would otherwise be considered crimes if the individuals committing them were older. The term delinquent usually refers to juvenile delinquency, and is also generalised to refer to a young person who behaves an unacceptable way.

In criminal justice systems, a youth detention center, known as a juvenile detention center (JDC), juvenile detention, juvenile jail, juvenile hall, or more colloquially as juvie/juvy or the Juvey Joint, also sometimes referred to as observation home or remand home is a prison for people under the age of majority, to which they have been sentenced and committed for a period of time, or detained on a short-term basis while awaiting trial or placement in a long-term care program. Juveniles go through a separate court system, the juvenile court, which sentences or commits juveniles to a certain program or facility.