The Comoros ( , ; جزر القمر , Juzur al-Qumur), officially the Union of the Comoros ('Union des Comores', الإتّحاد القمريّ , Al-Ittiḥād al-Qumuriyy) is an island nation in the Indian Ocean, located off the eastern coast of Africa on the northern end of the Mozambique Channel between northern Madagascar and northeastern Mozambique. The nearest countries to the Comoros are Mozambique, Tanzania, Madagascar, and the Seychelles. Prior to 2002, it was known officially as the Islamic Federal Republic of the Comoros. At 2,235 km² (863 sq mi) the Comoros is the third smallest African nation by area; and with a population estimated at 798,000 it is the sixth smallest African nation by population (though it has one of the highest population densities in Africa). Its name derives from the Arabic word ("moon").

The country officially consists of the four islands in the volcanic Comoros archipelago: Ngazidja (Grande Comore), Mwali (Mohéli), Nzwani (Anjouan), and Mahoré (Mayotte), as well as many smaller islands. However, the government of the Union of the Comoros (or its predecessors since independence) has never administered the island of Mayotte, which France considers an overseas community and still administers. Since Mayotte was the only island in the archipelago that voted against independence from France, and France has vetoed United Nations Security Council resolutions that would affirm Comorian sovereignty over the island, control was never passed to the Comoros.

The country is notable for its diverse culture and history, as a nation formed at the crossroads of many civilizations. It has three official languages—Comorian (Shikomor), Arabic, and French, and it is the only state to be a member of each of the African Union, Francophonie, Organisation of the Islamic Conference, Arab League, and Indian Ocean Commission, among other international organizations. However it has had a troubled history since independence in 1975, marked by an inordinate number of coups d'état.