Island nations are sovereign states made up entirely of islands, with no land border to a continent. This reference lists island and archipelago countries with their ocean basin, land area, population, and capital, so you can compare them side by side.
How it works
A country qualifies as an island nation when all of its territory is islands. That spans two shapes:
- Single-island states such as Sri Lanka, Cuba, or Iceland.
- Archipelago states such as Indonesia, the Philippines, and Japan, made up of many islands.
Each entry records the ocean basin (Pacific, Atlantic, Indian, or a regional sea), the land area in square kilometres, the population, and the capital, letting you compare scale from giant Indonesia down to microstates like Nauru.
Notable contrasts across the reference
The range of island nations is extraordinary. By land area, Indonesia spans more than 1.9 million square kilometres across over 17,000 islands, while Nauru — the smallest — covers roughly 21 square kilometres. By population, Indonesia is home to more than 270 million people, making it among the world’s most populous countries by any measure; the Maldives and several Pacific microstates number in the tens of thousands.
Some further contrasts worth noting:
- Iceland (Atlantic, ~103,000 km²) is one of the largest single-island states and has one of the smallest populations per area among developed nations.
- Trinidad and Tobago anchors the southern Caribbean and is notable for a mixed economy based on oil and natural gas, distinguishing it from its primarily tourism-based neighbours.
- Singapore (about 733 km²) is among the most densely populated sovereign territories on Earth, fitting over five million people into a city-state on a single main island.
- Fiji covers more than 330 islands across the South Pacific, with fewer than one million residents spread across them.
Ocean basin groupings and why they matter
Grouping by ocean basin is more than geography — it reflects shared political and economic realities.
- Pacific island states (Fiji, Samoa, Tonga, the Federated States of Micronesia, Kiribati, and others) share common challenges around sea-level rise, cyclone exposure, and dependence on foreign aid or tourism.
- Caribbean nations (Jamaica, Barbados, Saint Lucia, Trinidad and Tobago, and others) share the Atlantic basin and a broadly tourism-driven economy, though Trinidad and Tobago stands out for its hydrocarbon exports.
- Indian Ocean states (Sri Lanka, Maldives, Comoros, Seychelles, Mauritius) range from the densely populated Sri Lanka to the remote coral atolls of the Maldives, which sit at extremely low elevation.
Tips and notes
Australia is geographically the largest island but is usually treated as a continental country, so this list focuses on smaller states whose identity is defined by being islands. Many small island states are acutely exposed to sea-level rise — countries like Kiribati and the Maldives have land that averages only a few metres above sea level, raising long-term questions about their territorial future. Use the ocean filter to compare states that share regional governance bodies, climate agreements, and economic structures.