in political science, a multiheaded body created to perform a particular function, whether it be administrative, legislative, or judicial in nature. In the United Kingdom commissions are mostly used for special investigations and are distinguished according to their terms of appointment as royal, statutory, or departmental. In general these are appointed for a particular purpose when it is desired that an administrative body (the commission) be independent of the government department concerned. Investigating commissions are less frequently employed in the United States, where their functions are largely performed by legislative committees. In the United States most commissions are charged with the execution or enforcement of statutes. The most important commissions are vested with regulatory powers and are known as regulatory agencies (see regulatory agency).

Some American cities and towns are administered by an elected commission, usually consisting of three, five, or seven commissioners. Each commissioner serves as the head of one or more departments. In most cities, however, the commission system has given way to the council–manager system. Commission systems are still widely used to govern specific aspects of local government, such as parks, schools, water, and airports. This administrative method is especially popular for public-school systems, where the commission itself may appoint a professional administrator. The commission form is also used in such state agencies as utility commissions, worker's compensation boards, boards of health and education, and unemployment compensation commissions.