一个主权国家的外交政策，或者称为对外政策，包含由官方所采取，有关其自身利益的策略，以维护其国家利益并在当时的国际关系环境底下达到其目的。此等政策会在该国与其他国家交互时具策略性地实行。近年来，由于全球化和跨国活动的程度日益深化，国家实体亦有需要跟非国家实体交互。上述的交互持续被评价和监察，以祈把多边国际合作的利益最大化。因着国家利益极为显著的重要性，外交政策均由政府通过高层决策过程制定。要满足国家利益可以通过跟其他国家和平合作，又或通过剥削。一般来说，制定外交政策是由政府首脑及外长负责。一些国家的立法机关对外交政策有显著的监督权力。

A country's foreign policy, also called foreign relations policy, consists of self-interest strategies chosen by the state to safeguard its national interests and to achieve goals within its international relations milieu. The approaches are strategically employed to interact with other countries. The study of such strategies is called foreign policy analysis. In recent times, due to the deepening level of globalization and transnational activities, the states will also have to interact with non-state actors. The aforementioned interaction is evaluated and monitored in attempts to maximize benefits of multilateral international cooperation. Since the national interests are paramount, foreign policies are designed by the government through high-level decision making processes. National interests accomplishment can occur as a result of peaceful cooperation with other nations, or through exploitation. Usually, creating foreign policy is the job of the head of government and the foreign minister (or equivalent). In some countries the legislature also has considerable effects. Foreign policies of countries have varying rates of change and scopes of intent, which can be affected by factors that change the perceived national interests or even affect the stability of the country itself. The foreign policy of one country can have profund and lasting impact on many other countries and on the course of international relations as a whole, such as the Monroe Doctrine conflicting with the mercantilist policies of 19th century European countries and the goals of independence of newly formed Central American and South American countries.