特命全权公使，通常简称公使，是一国元首向驻在国元首派遣的等级第二高的外交代表，级别仅次于特命全权大使，但实质地位、职务以及所享受的外交特权与豁免同大使相同。

特命全权公使原为君主制国家的元首向共和制国家的政府派出的全权代表，后演变为大国向小国派出的外交代表。第二次世界大战后，根据联合国所有国家不分大小一律平等的原则，各国开始向所有建交国家派遣大使。

In diplomacy, an "Envoy Extraordinary and Minister Plenipotentiary", in short Envoy, is under the terms of the Congress of Vienna of 1815, a diplomat of the second class, ranking between an Ambassador and a Minister Resident.

Usually just referred to as a Minister, an Envoy is a diplomatic representative, not considered a representative of the head of state, but nonetheless with plenipotentiary powers (i.e. full authority to represent the government). A diplomatic mission headed by an Envoy would be called a Legation rather than an Embassy. Envoys are entitled to use the style "His/Her Excellency".