In law, a sentence is the punishment for a crime ordered by a trial court after conviction in a criminal procedure, normally at the conclusion of a trial. A sentence may consist of imprisonment, a fine, or other sanctions. Sentences for multiple crimes may be a concurrent sentence, where sentences of imprisonment are all served together at the same time, or a consecutive sentence, in which the period of imprisonment is the sum of all sentences served one after the other. Additional sentences include intermediate, which allows an inmate to be free for about 8 hours a day for work purposes; determinate, which is fixed on a number of days, months, or years; and indeterminate or bifurcated, which mandates the minimum period be served in an institutional setting such as a prison followed by street time period of parole, supervised release or probation until the total sentence is completed.

If a sentence is reduced to a less harsh punishment, then the sentence is said to have been mitigated or commuted. Rarely depending on circumstances, murder charges are mitigated and reduced to manslaughter charges. However, in certain legal systems, a defendant may be punished beyond the terms of the sentence, through phenomena including social stigma, loss of governmental benefits, or collectively, the collateral consequences of criminal charges.

Statutes generally specify the highest penalties that may be imposed for certain offenses, and sentencing guidelines often mandate the minimum and maximum imprisonment terms imposed upon an offender, which is then left to the discretion of the trial court. However, in some jurisdictions, prosecutors have great influence over the punishments actually handed down, by virtue of their discretion to decide what offenses to charge the offender with and what facts they will seek to prove or to ask the defendant to stipulate to in a plea agreement. It has been argued that legislators have an incentive to enact tougher sentences than even they would like to see applied to the typical defendant since they recognize that the blame for an inadequate sentencing range to handle a particularly egregious crime would fall upon legislators, but the blame for excessive punishments would fall upon prosecutors.

Sentencing law sometimes includes cliffs that result in much stiffer penalties when certain facts apply. For instance, an armed career criminal or habitual offender law may subject a defendant to a significant increase in his sentence if he commits a third offense of a certain kind. This makes it difficult for fine gradations in punishments to be achieved.