Cabinet is the body of ministers or chief executives of government departments who form the senior officials of a political system. In a presidential system the President delegates a great deal of his or her executive powers to the Cabinet, and members of the Cabinet are responsible for administering those portions of the executive branch that they oversee.

The term cabinet originated in the United States with George Washington who began the custom of consulting regularly with department heads as a group, rather than individually. Over the years, as administrative duties grew and different problems arose, new executive departments were created and by the early 21st century, the U.S. cabinet consisted of 15 department heads or secretaries.

In parliamentary systems, where the ultimate source of executive authority is the head of government (called a prime minister in the three countries that use the Westminster system), the cabinet is a very important part of government. In fact, the majority of legislation in parliamentary systems comes from the cabinet and its ministries.

In parliamentary systems, the cabinet is also a very effective mechanism for managing the competing factions of a political party or coalition. This is achieved because cabinet members are selected from the ranks of sitting legislators, and a member can only serve as a Cabinet member if he or she is a sitting Member of Parliament. In the United States, Cabinet officers are nominated by the President and then presented to the Senate for confirmation.