小岛屿国家联盟（Alliance of Small Island States，AOSIS) 是一个低海岸国家与小岛屿国家的政府间组织，成立于1990年，其宗旨是加强小岛屿发展中国家（Small Island Developing States，SIDS）在应对全球气候变化中的声音。AOSIS早在1994年《京都议定书》谈判中推出第一份草案之后便已相当活跃。

截至2008年3月，AOSIS共有来自全世界的39个成员及4个观察员，其中有37个联合国会员。该联盟代表了28%的发展中国家，以及20%的联合国会员总数。

Alliance of Small Island States (AOSIS) is an intergovernmental organization of low-lying coastal and small island countries. Established in 1990, the main purpose of the alliance is to consolidate the voices of Small Island Developing States (SIDS) to address global warming. AOSIS has been very active from its inception, putting forward the first draft text in the Kyoto Protocol negotiations as early as 1994. At the 2013 Warsaw climate change conference, AOSIS also pushed for the establishment of an international mechanism on loss and damages stressed by the wreckage of Supertyphoon Haiyan. As the existence of many AOSIS states are put at risk by climate change AOSIS has threatened lawsuits. The results of a recent review of the literature show that potential liability for climate change-related losses for the Alliance of Small Island States is over $570 trillion.