The Lord High Treasurer of Ireland was the head of the Exchequer of Ireland, and chief financial officer of the Kingdom of Ireland. The designation High was added in 1695.

After the Acts of Union 1800 created the United Kingdom of Great Britain and Ireland, the Consolidated Fund Act 1816 merged the Irish Inferior Exchequer into the British Treasury with effect from 1817.

The act also mandated that the post of Lord High Treasurer of Ireland could only be held together with the post of Treasurer of the Exchequer, with the person holding both being Lord High Treasurer. If no person is appointed to the combined positions, then the Lord High Treasurer of Ireland is placed in commission and represented by the Lords Commissioners of the Treasury, as has been the case continuously since 1816.

The Superior Irish Exchequer, or Court of Exchequer, remained, led by the Chief Baron of the Irish Exchequer.