The European Economic Community (EEC) was a regional organisation created by the Treaty of Rome of 1957, aiming to foster economic integration among its member states. It was subsequently renamed the European Community (EC) upon becoming integrated into the first pillar of the newly formed European Union in 1993. In the popular language, however, the singular European Community was sometimes inaccurately used in the wider sense of the plural European Communities, in spite of the latter designation covering all the three constituent entities of the first pillar.

In 2009, the EC formally ceased to exist and its institutions were directly absorbed by the EU. This made the Union the formal successor institution of the Community.

The Community's initial aim was to bring about economic integration, including a common market and customs union, among its six founding members: Belgium, France, Italy, Luxembourg, the Netherlands and West Germany. It gained a common set of institutions along with the European Coal and Steel Community (ECSC) and the European Atomic Energy Community (EURATOM) as one of the European Communities under the 1965 Merger Treaty (Treaty of Brussels). In 1993 a complete single market was achieved, known as the internal market, which allowed for the free movement of goods, capital, services, and people within the EEC. In 1994 the internal market was formalised by the EEA agreement. This agreement also extended the internal market to include most of the member states of the European Free Trade Association, forming the European Economic Area, which encompasses 15 countries.

Upon the entry into force of the Maastricht Treaty in 1993, the EEC was renamed the European Community to reflect that it covered a wider range than economic policy. This was also when the three European Communities, including the EC, were collectively made to constitute the first of the three pillars of the European Union, which the treaty also founded. The EC existed in this form until it was abolished by the 2009 Treaty of Lisbon, which incorporated the EC's institutions into the EU's wider framework and provided that the EU would "replace and succeed the European Community".

The EEC was also known as the European Common Market in the English-speaking countries and sometimes referred to as the European Community even before it was officially renamed as such in 1993.