define executive agency
From Wikipedia, the free encyclopedia. An executive agency is a part of a government department that is treated as managerially and budgetarily separate in order to carry out some part of the executive functions of the United Kingdom government, Scottish Government, Welsh Government or Northern Ireland Executive.xecutive agencies are machinery of government devices distinct both from non-ministerial government departments and non-departmental public bodies (or  quangos ), each of which enjoy a real legal and constitutional separation from ministerial control.