半官方机构（英语：Quasi-Non-Governmental Organisations，简称：QUANGO），由政府创立的机构、委员会、法团或组织，其编制虽与政府相似，但并不属于政府的一部份。一般而言，这些机构会被视会独立机构，但财政上常依赖政府支持，而部份主要领导亦由政府以借调形式派遣担任。政府对此等机构的管理委员会或主要领导的委任通常具最终（甚或独一）的决定权。

半官方机构在英国、澳洲、爱尔兰、香港甚为通行。香港现存的半官方机构例子包括：香港出口信用保险局、香港生产力促进局、香港金融管理局、香港旅游发展局、香港体育学院、香港学术及职业资历评审局及消费者委员会等。

A government or state agency, often an appointed commission, is a permanent or semi-permanent organization in the machinery of government that is responsible for the oversight and administration of specific functions, such as an intelligence agency. There is a notable variety of agency types. Although usage differs, a government agency is normally distinct both from a department or ministry, and other types of public body established by government. The functions of an agency are normally executive in character, since different types of organizations (such as commissions) are most often constituted in an advisory role—this distinction is often blurred in practice however.