How many countries are in Southeast Asia?
There are 11 countries in Southeast Asia: Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, Timor-Leste and Vietnam.
The 11 countries of Southeast Asia are Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand, Timor-Leste and Vietnam. They are home to about 700.0 million people.
Since 2025 this list matches the membership of ASEAN, the Association of Southeast Asian Nations, exactly: Timor-Leste became its 11th member in October 2025, after the original ten (Brunei, Cambodia, Indonesia, Laos, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam).
Mainland and maritime Southeast Asia
Geographers split the region in two. Mainland Southeast Asia (the Indochinese peninsula) is Myanmar, Thailand, Laos, Cambodia and Vietnam, plus Peninsular Malaysia, linked by the Mekong and other great rivers. Maritime Southeast Asia is Indonesia, the Philippines, Singapore, Brunei, Timor-Leste and East Malaysia on Borneo. Indonesia and the Philippines together have more than 25,000 islands. Laos is the region's only landlocked country.
Southeast Asian countries by population
| Country | Capital | Population | Area (km²) |
|---|---|---|---|
| Indonesia | Jakarta | 285,721,236 | 1,904,569 |
| Philippines | Manila | 116,786,962 | 300,000 |
| Vietnam | Hanoi | 101,598,527 | 331,212 |
| Thailand | Bangkok | 71,619,863 | 513,120 |
| Myanmar | Naypyidaw | 54,850,648 | 676,578 |
| Malaysia | Kuala Lumpur | 35,977,838 | 330,803 |
| Cambodia | Phnom Penh | 17,847,982 | 181,035 |
| Laos | Vientiane | 7,873,046 | 236,800 |
| Singapore | Singapore | 5,870,750 | 745 |
| Timor-Leste | Dili | 1,418,517 | 14,874 |
| Brunei | Bandar Seri Begawan | 466,330 | 5,765 |
Indonesia dominates, with about 41% of the region's people and the largest land area. At the other extreme, Brunei has under half a million people and Singapore is the smallest by area.
Explore the region on the Southeast Asia map.
Population: UN World Population Prospects 2024 (2025 estimates). Area: total area including inland water, standard UN / national reference figures.
Related questions
Is Timor-Leste part of Southeast Asia?
Yes. It occupies the eastern half of the island of Timor and is classed as Southeast Asian by the UN. It joined ASEAN as the 11th member in 2025.
Is Papua New Guinea in Southeast Asia?
No. Although it shares the island of New Guinea with Indonesia, Papua New Guinea is classed as part of Oceania (Melanesia). It holds observer status at ASEAN.