What Country Starts with O? Only One Nation Does

If you’ve ever tried to list a country that starts with O, you probably stumbled almost immediately. That’s because there’s only one sovereign nation with an English name beginning with that letter — and it’s a Middle Eastern monarchy with a rich history. Oman, positioned at the mouth of the Persian Gulf, is home to about 5.6 million people and has been independent since the 17th century. Here’s what makes that single O country so distinctive — and why no other modern nation shares its initial.

Countries starting with O: 1 ·
Country name: Oman ·
Population: ~5.6 million (2024 estimate) ·
Capital: Muscat ·
Official language: Arabic ·
UN member: Yes (since 1971)

Among the handful of details that define Oman’s identity, these ten facts stand out.

The implication: Oman’s profile holds the only slot for the letter O in modern sovereign-state lists

What country starts with O?

What is the official name of the country?

• The sovereign state is officially the Sultanate of Oman. English-language country lists identify Oman as the only sovereign state whose English name starts with the letter O (QuillBot (word-reference tool)).
• It is classified as an absolute monarchy by some sources, with the sultan serving as head of state and government (Wikipedia (community encyclopedia)).

What is the capital city?

• The capital is Muscat, located on the Gulf of Oman (Britannica (authoritative encyclopedia)).
• It is the largest city and the political, economic, and cultural center of the country.

What are some key facts about Oman?

• Oman’s estimated population for 2026 is 5,414,000 (Britannica). Current estimates place it around 5.6 million.
• The currency is the Omani Rial (OMR), with an exchange rate of 1 USD = 0.385 OMR (Britannica).
• Oman is strategically located at the mouth of the Gulf, on the south-eastern corner of the Arabian Peninsula (BBC News (global news service)).
• It is the oldest independent state in the Arab world, with a history stretching back centuries (BBC News).

How many countries start with O?

Are there any territories or dependencies starting with O?

• No non-sovereign territory or dependency whose English name starts with O meets the criteria for UN membership or general sovereign state recognition. The WHO country index includes only Oman under O (WHO Data (global health agency)).
• Okinawa is often mentioned, but it is a prefecture of Japan, not a sovereign country (World Atlas (geography reference)).

Why so few countries with O?

• Geographic naming conventions in English rarely favor the letter O for country names. Most nations derive their names from indigenous terms, colonial history, or geographical features — and few of those happen to start with O (EPFL dlab list of sovereign states (academic reference)).
• Historical empires such as the Ottoman Empire (modern Turkey) and the Oyo Empire (in present-day Nigeria) once existed but are no longer sovereign states (World Atlas).

What are 5 countries starting with O?

Why can’t I find five countries?

• There are simply not enough sovereign states. Only one exists today: Oman. All standard lists of sovereign states, including the U.S. Department of State’s independent-states list, confirm this (U.S. Department of State (official diplomatic lists)).
• Some online sources may list O as a trick question for this very reason.

What about historical countries or territories?

• Historical entities like the Orange Free State (a Boer republic in 19th-century southern Africa) and the Ottoman Empire existed but are not current sovereign nations (World Atlas).
• Other regions such as Olt (a county in Romania) or Ontario (a province of Canada) are subnational divisions, not countries.

For travelers and trivia buffs alike, the letter O remains the exclusive property of Oman — a reminder that sometimes the rarest answers are also the most fascinating. For anyone searching “what country starts with O,” the clear path is to learn about this Arabian sultanate and its unique place in the world’s alphabet.