Parole is a form of conditional release of a prison inmate before the completion of their sentence, where the prisoner agrees to abide by certain behavioral conditions, including checking in with their designated parole officers, or else they may be rearrested and returned to prison. The term "parole" comes from the French word "parol," meaning "word" or "promise". Parole differs from pardon, amnesty, or commutation of sentence in that parolees are still considered to be serving their sentences and may be returned to prison if they violate the conditions of their parole.

Under the traditional parole system, parole is a privilege for prisoners who seem capable of reintegrating into society. Its not a right, and authorities retain the discretion to deny parole to prisoners they deem dangerous. Many prisoners become eligible for parole, and after a parole board finds that a prisoner is eligible, the inmate appears at a parole hearing. If granted parole, the parolee is released and lives free in society but under the continued supervision of the prison authority.

The supervision practices of increased drug testing, intensive supervision, unannounced visits, and home confinement are widely used today. Parole boards may be autonomous panels with administrative support from a department of corrections or a community corrections agency, or they may be a part of the executive branch of state government. Probation is very similar to parole, except that probationers have not served prison time on their suspended sentence, and the sentencing judge maintains jurisdiction over the probationer.