Law, signifies the periodical progress of a legal tribunal for the sake of carrying out the administration of the law in the several provinces of a country. It has long been applied to the journey or progress which the judges have been in the habit of making twice every year, through the several counties of England, to hold courts and administer justice, where recourse could not be had to the king's court at Westminster. The country, including Wales, is now divided into eight circuits, viz., the Home, the Norfolk, the Midland, the Oxford, the Western, the Northern, the North Wales, and the South Wales circuit. For a short period the insolvency commissioners made circuits three times a-year, but in 1847 the duties of the circuits were transferred to the new county courts.

In Scotland the judges of the supreme criminal court, or High Court of Justiciary, form also three separate circuit courts, consisting of two judges each; and the kingdom, with the exception of the Lothians, is divided into corresponding districts, called the Northern, Western, and Southern Circuits. In certain burghs of each circuit two courts are held in the year, in spring and autumn, called Circuit Courts. One more is now held at Glasgow during the Christmas recess.

Ireland is divided into the North-East and the North-West Circuits, the Home Circuit, and those of Leinster, Connaught, and Munster.