Ambassador, Or Embassador, a term generally applied to the highest class of diplomatic representatives in foreign countries. In an official sense it designates only those who are accredited by one potentate to another, and who represent the sovereign himself, while ministers plenipotentiary and envoys extraordinary, although accredited to the crown, represent only the state, and not the person of its chief. The queen of England, for instance, sends ambassadors to the most influential sovereigns, but only a minister plenipotentiary to the United States. The American minister plenipotentiary and envoy extraordinary (the title ambassador being not often used, although it is mentioned in the act of congress of 1856 relating to the diplomatic service) is consequently outranked at European courts by the ambassadors of the pettiest sovereign princes. The legates and nuncios of the pope are entitled to the same social and diplomatic privileges as ambassadors. An ambassador may at all times demand a personal interview with the sovereign as a matter of right, while the minister plenipotentiary can only claim an audience as a favor. Ambassadors extraordinary are those sent on special missions, and occupy a still more exalted position than those called ordinary, who permanently reside at a court.

Ambassadors in the principal non-Christian countries enjoy extra-territorial rights, based upon the fiction that they carry along with them the whole territory of their sovereign, so that the country represented is deemed to be present in China, Japan, Turkey, etc, as well as its sovereign himself, in the person of the ambassador. The extra-territorial rights of ambassadors and other official representatives of Christian powers in the East are guaranteed by treaties, and are predicated upon their jurisdiction over more or less extensive communities of their countrymen and over other persons under their protection.