联系邦，也称自由联合国，是指在一定程度上与另一个较大的主权国家在政治上有着一种自由的合作伙伴关系的主权国家的特殊政治关系。其中，「自由联合」关系仅限于联合国托管理事会指定的美国的《自由联合条约》或英国的《联系邦法》，及其相关的国家。联系邦不是受保护国，所有的联系邦皆为国际法阐明的主权国家或拥有潜在的独立主权。

在非正式场合，它可以有更广泛的定义。例如国家联盟是一种类自由联合，因为至少一个政府子单位享有像联邦子单位一样的独立主权。然而在国际法中，它是一种截然不同的情况，因为子单位不是独立的国际实体也并没有任何潜在的独立主权。

An associated state is the minor partner in a formal, free relationship between a political territory with a degree of statehood and a (usually larger) nation, for which no other specific term, such as protectorate, is adopted. The details of such free association are contained in United Nations General Assembly resolution 1541 (XV) Principle VI, a Compact of Free Association or Associated Statehood Act and are specific to the countries involved. In the case of the Cook Islands and Niue, the details of their free association arrangement are contained in several documents, such as their respective constitutions, the 1983 Exchange of Letters between the governments of New Zealand and the Cook Islands, and the 2001 Joint Centenary Declaration. Free associated states can be described as independent or not, but free association is not a qualification of an entity's statehood or status as a subject of international law.