A chargé d'affaires, plural chargés d'affaires, often shortened to chargé (French) and sometimes in colloquial English to charge-D, is a diplomat who serves as an embassy's chief of mission in the absence of the ambassador. The term is French for "charged with business", meaning they are responsible for the duties of an ambassador. Chargé is masculine in gender; the feminine form is chargée d'affaires.

A diplomat is a person appointed by a state, intergovernmental, or nongovernmental institution to conduct diplomacy with one or more other states or international organizations.