A prosecutor is a legal representative of the prosecution in states with either the adversarial system, which is adopted in common law, or inquisitorial system, which is adopted in civil law. The prosecution is the legal party responsible for presenting the case in a criminal trial against the defendant, an individual accused of breaking the law. Typically, the prosecutor represents the state or the government in the case brought against the accused person.

The Crown Office and Procurator Fiscal Service is the independent public prosecution service for Scotland, and is a Ministerial Department of the Scottish Government. The department is headed by His Majesty's Lord Advocate, who under the Scottish legal system is responsible for prosecution, along with the sheriffdom procurators fiscal. In Scotland, virtually all prosecution of criminal offences is undertaken by the Crown. Private prosecutions are extremely rare.