A landlocked country is a country that does not have territory connected to an ocean or whose coastlines lie on endorheic basins. There are currently 44 landlocked countries and four landlocked de facto states. Kazakhstan is the world's largest landlocked country while Ethiopia is the world's most populous landlocked country.

In 1990, there were only 30 landlocked countries in the world. The dissolutions of the Soviet Union and Czechoslovakia; the breakup of Yugoslavia; the independence referendums of South Ossetia (partially recognized), Eritrea, Montenegro, South Sudan, and the Luhansk People's Republic (partially recognized); and the unilateral declaration of independence of Kosovo (partially recognized) created 15 new landlocked countries and five partially recognized landlocked states while the former landlocked country of Czechoslovakia ceased to exist on 1 January 1993. On 5 October 2022, the Luhansk People's Republic was annexed by Russia and ceased to exist as a de facto landlocked state.

Generally, being landlocked creates some political and economic disadvantages that having access to international waters would avoid. For this reason, nations large and small throughout history have sought to gain access to open waters, even at great expense in wealth, bloodshed, and political capital.

The economic disadvantages of being landlocked can be alleviated or aggravated depending on degree of development, surrounding trade routes and freedom of trade, language barriers, and other considerations. Some landlocked countries in Europe are affluent, such as Andorra, Austria, Liechtenstein, Luxembourg, San Marino, Switzerland, and Vatican City, all of which, excluding Luxembourg (a founding member of NATO), frequently employ neutrality in global political issues. However, 32 out of the 44 landlocked countries, including all the landlocked countries in Africa, Asia, and South America, have been classified as the Landlocked Developing Countries (LLDCs) by the United Nations. Nine of the twelve countries with the lowest Human Development Indices (HDI) are landlocked. International initiatives are aimed at reducing inequalities resulting from issues such as these, such as the United Nations Sustainable Development Goal 10, which aims to reduce inequality substantially by 2030.