The Chief Secretary to the Treasury is a ministerial office in the government of the United Kingdom and is the second most senior ministerial office in HM Treasury, after the Chancellor of the Exchequer. The office was created in 1961 to share the burden of representing HM Treasury with the chancellor.

His Majesty's Treasury, occasionally referred to as the Exchequer, or more informally the Treasury, is a ministerial department of the Government of the United Kingdom. It is responsible for developing and executing the government's public finance policy and economic policy. The Treasury maintains the Online System for Central Accounting and Reporting, the replacement for the Combined Online Information System, which itemises departmental spending under thousands of category headings, and from which the Whole of Government Accounts annual financial statements are produced.