The Exchequer of Ireland was a body in the Kingdom of Ireland tasked with collecting royal revenue. Modelled on the English Exchequer, it was created in 1210 after King John of England applied English law and legal structure to his Lordship of Ireland. The Exchequer was divided into two parts; the Superior Exchequer, which acted as a court of equity and revenue in a way similar to the English Exchequer of Pleas, and the Inferior Exchequer, which directly collected revenue from those who owed The Crown money, principally rents for Crown lands. The Exchequer primarily worked in a way similar to the English legal system, holding a similar jurisdiction (down to the use of the Writ of Quominus to take over cases from the Irish Court of Chancery). Following the Act of Union 1800, which incorporated Ireland into the United Kingdom, the Exchequer was merged with the English Exchequer in 1817 and ceased to function as an independent body, although the Irish Court of Exchequer, like other Irish courts, remained separate from the English equivalent.

The Exchequer of Ireland was formed in 1210, when King John applied English law, which included the Exchequer, to Ireland. Like the English Exchequer, the Exchequer of Ireland was divided into two parts; the judicial, or Superior Exchequer, which was a court, and the receipt, or Inferior Exchequer, which was tasked with receiving rents and other revenues for The Crown. The principal purpose of the Exchequer was to act as a treasury, taking in revenues, with the receipt department collecting money and the court acting in cases where this money was not paid, or where there was some dispute over it.^[1] As with the English Exchequer, the judicial part was a court of both law and equity, and was occasionally known as the Irish Exchequer of Pleas, after the English body.^[2] The Inferior Exchequer, tasked with collecting revenues, remained part of the Exchequer long after the English Inferior Exchequer had become a distinct body called the Treasury.^[3] The Exchequer was finally dissolved in 1817, when it was amalgamated with the Exchequer of Great Britain following the Act of Union 1800.^[4]

The "Red Book of the Irish Exchequer" (so-called by analogy with the English Red Book of the Exchequer) was a 14th-century compilation of Exchequer practice, including the text of the Magna Carta Hiberniae, destroyed in the 1922 Four Courts explosion.^[5]

For much of its history it was based in Dublin, but in the fourteenth century, it moved in 1361, with some of the royal courts, to Carlow, as being more central for the Anglo-Irish government. However, Carlow was raided and burnt by the Irish clans of Leinster at least three times. As a result, the Exchequer moved back to Dublin for a time in the 1360s and eventually the entire administration returned there in 1393.^[6]

Court hearings were held before the Barons of the Exchequer of Ireland, along with the Chancellor and Treasurer; in practice, only the Barons attended. The Court's jurisdiction was over matters pertaining to The Crown's revenues, although the Writ of Quominus was used as a work of legal fiction to widen its remit. The procedure used was similar to that in the Court of Chancery, and as such the officials of the court could only be sued through the Exchequer, not through any other body, particularly if the case was about their professional actions.^[7] As a result of the Writ of Quominus, anyone identified as a debtor to The Crown could bring a case. Every Irish case which involved the King and his revenue was brought to the Irish Exchequer of Pleas; if brought to another court, it would be relocated to the Exchequer.^[8] All cases were recorded, first in the Plea rolls and then in the Pipe Rolls, which recorded the revenues and debts owed to The Crown.^[9]