This is a list of countries that have a land border with only one other country. Some on this list have a maritime border with additional countries. Some countries, which are not listed here, have no land border but do have a maritime border with a single other country, such as Sri Lanka. There are generally three arrangements by which a country would have a single land border: Territory leased or ceded by one country to another for perpetual use, but not in sovereignty, such as Guantanamo Bay Naval Base in Cuba, or memorials, such as the American Cemetery in France, do not constitute true territorial borders because the land occupied remains a formal part of the host country. This list is based on the Correlates of War Direct Contiguity data set, with maritime causeways and bridges not being counted.

Countries bordering only one other country

This section considers only sovereign countries, not constituent countries like Wales and Scotland, which border only England.

Landlocked

With coast

Causeways, bridges, and tunnels

Often called fixed crossings or fixed links, transportation corridors constructed to cross bodies of water without any intermittent connections such as ferries or ships may be between different states. These may be considered artificial "persistent" borderpoints for land vehicles or pedestrians, but are not typically considered land borders given their need for continuous operation and maintenance, as well as their ease of volume control or closure by either state. Two countries are islands and have no land borders, but maintain fixed borderpoints with other nations.

Dependent territories

In some cases, a dependent territory of one nation borders another nation.

Integral parts of sovereign states

In most cases, an integral part of a larger country shares a border with another nation.

Historical

Many countries historically had only one neighbour. Some no longer exist while others now have either no land borders or borders with more than one nation due to border changes.