An island nation is a country that is wholly confined to an island or islands. Forty-seven of the world's countries are island nations, including most of the smallest ones.

Island nations can be divided in two approximate groups. There are those that are large, relatively populous, and usually close to a continent. These include the United Kingdom, Japan, Indonesia, the Philippines, and Madagascar. These countries typically share cultural and political similarities with their continental neighbours. Their island status has sometimes been an important advantage that has isolated them from invasion and made them important in regional trade because of their locations and the maritime abilities of the population. Australia can be considered this category of nation taken to an extreme: an island nation so large it is considered a continent.

Smaller island nations such as the Comoros, the Bahamas, Tonga, and the Maldives tend to be very different from continental nations. The small size usually means there is little agricultural land and rarely many natural resources. However, in modern times smaller island nations around the world have become centres for tourism, which in many is today the dominant industry.

Some island nations are centered on one or two major islands, such as the United Kingdom and Fiji. Others are spread out over hundreds or thousands of smaller islands, such as Indonesia or the Maldives. Some island nations share their islands with other countries; these include the Republic of Ireland, Haiti, and Papua New Guinea. The opposite of an island nation is a landlocked one.

See also

• List of island nations
• List of islands (by country)
• List of countries
• Category:Island nations