Several past and present states have declared themselves socialist states or in the process of building socialism. The majority of self-declared socialist countries have been Marxist–Leninist or inspired by it, following the model of the Soviet Union or some form of people's or national democracy. They share a common definition of socialism, and they refer to themselves as socialist states on the road to communism with a leading vanguard party structure, hence they are often called communist states. Meanwhile, the countries in the non-Marxist–Leninist category represent a wide variety of different interpretations of the term socialism, and in many cases the countries do not define what they mean by it. Modern uses of the term socialism are wide in meaning and interpretation. Because a sovereign state is a different entity from the political party that governs that state at any given time, a country may be ruled by a socialist party without the country itself claiming to be socialist or the socialist party being written into the constitution. This has occurred in both one-party and multi-party political systems. In particular, there are numerous cases of social democratic and democratic socialist parties winning elections in liberal democratic states and ruling for a number of terms until a different party wins the elections. While socialist parties have won many elections around the world and most elections in the Nordic countries, none of those countries have adopted socialism as a state ideology or written the party into the constitution. Several countries with liberal democratic constitutions mention socialism. India is a democracy that has been governed by non-socialist parties on many occasions, but its constitution makes references to socialism. Certain other countries, such as Hungary, Myanmar, and Poland have constitutions that make references to their communist and socialist past by recognizing or condemning it, but without claiming to be socialist in the present.

Overview

Self-identification is the only criterion used by the list, therefore it includes all countries that have claimed to be socialist, even if their claims are disputed. All countries that have not claimed to be socialist are excluded, even in cases where certain outside observers regarded those countries as socialist. Mao Zedong and the Communist Party of China considered the Taiping Heavenly Kingdom to be a proto-communist state, although the kingdom never declared itself socialist, hence it is not included on this list. The list includes countries that assert in their constitutions that they are based on socialism, regardless of their economic or political system. It does not list countries that do not have constitutional references to socialism as socialist states, even in cases where the government is currently run by a socialist party or other left-wing (centre-left and far-left) parties. Inversely, countries that do maintain constitutional references to socialism are listed, even when those countries are governed by non-socialist parties. The list is best understood as a list of countries that explicitly claim to be socialist, and it does not reflect the actual economic systems themselves.

Current self-declared socialist states

Marxist–Leninist states

Non-Marxist–Leninist states

Socialist autonomous regions

These are territories that have claimed autonomy and declared themselves as socialist under some interpretation of the term. While these regions have created stable institutions of governance that have existed for a considerable period of time, they are not widely recognized as autonomous by the international community and officially are parts of other sovereign states under international law.

Former self-declared socialist states

Marxist–Leninist states

Non-Marxist–Leninist states

Ephemeral socialist states and polities

These are short-lived political entities that emerged during wars, revolutions, or unrest and declared themselves socialist under some interpretation of the term, but which did not survive long enough to create a stable government or achieve international recognition.

Non-socialist states with governing socialist parties

There are multiple states with socialist parties leading the government, sometimes together. Such states are not considered to be communist or socialist states because the countries themselves do not provide a constitutional role for their ruling socialist/communist parties or deem socialism a state ideology. This does not include socialist parties following social democracy, which have governed most of the Western world, much of Latin America, and other regions as part of the mainstream centre-left. Examples of previous direct communist or socialist party rule in non-socialist multi-party democracies include: