The Eastern Partnership (EaP) is a joint initiative of the European Union, together with its member states, and five (originally six) Eastern European countries. The EaP framework governs the EU's relationship with the post-Soviet states of Armenia, Azerbaijan, Georgia, Moldova, and Ukraine. Belarus halted its participation in the EaP in 2021.

The EaP is intended to provide a forum for discussions regarding trade, economic strategy, travel agreements, and other issues between the EU and its Eastern European neighbours. It also aims at building a common area of shared values of democracy, prosperity, stability, and increased cooperation. The project was initiated by Poland and a subsequent proposal was prepared in co-operation with Sweden. It was presented by the foreign ministers of Poland and Sweden at the EU's General Affairs and External Relations Council in Brussels on 26 May 2008. The Eastern Partnership was inaugurated by the EU in Prague, Czech Republic on 7 May 2009.

The first meeting of foreign ministers in the framework of the Eastern Partnership was held on 8 December 2009 in Brussels.

The Eastern Partnership (EaP) was established as a specific Eastern dimension of the European Neighbourhood Policy, which contains both a bilateral and multilateral track. The Eastern Partnership complements the Northern Dimension and the Union for the Mediterranean by providing an institutionalised forum for discussing visa agreements, free trade deals, and strategic partnership agreements with the EU's eastern neighbours, while avoiding the controversial topic of accession to the European Union. Its geographical scope consists of Armenia, Azerbaijan, Belarus, Georgia, Moldova, and Ukraine. Unlike the Union for the Mediterranean, the Eastern Partnership does not have its own secretariat, but is controlled directly by the European Commission.

In May 2008, Poland and Sweden put forward a joint proposal for an Eastern Partnership with Ukraine, Moldova, Armenia, Azerbaijan, and Georgia, with Russia and Belarus participating in some aspects. Eventually, Belarus joined the initiative as a full member, while Russia does not participate at all. The Polish foreign minister Radosław Sikorski said "We all know the EU has enlargement fatigue. We have to use this time to prepare as much as possible so that when the fatigue passes, membership becomes something natural" It was discussed at the European Council on 19 and 20 June 2008, along with the Union for the Mediterranean. The Czech Republic endorsed the proposal completely, while Bulgaria and Romania were cautious, fearing that the Black Sea Forum for Partnership and Dialogue and the Organization of the Black Sea Economic Cooperation could be undermined. Meanwhile, Germany, France, and others were not happy with the possibility that the Eastern Partnership could be seen as a stepping stone to membership (especially for Ukraine), while Poland and other Eastern states have explicitly welcomed this effect.

The Eastern Partnership was officially launched in May 2009 when the Czech Republic invited the leaders of the six members of the initiative. Meanwhile, Germany attended the summit to signal their alarm at the economic situation in the East. Russia accused the EU of trying to carve out a new sphere of influence, which the EU denied, stating that they were "responding to the demands of these countries...and the economic reality is that most of their trade is done with the EU".

The Eastern Partnership consists of the following 27 EU member states and six Eastern European post-Soviet states:

In addition, the above members, except Belarus, further participate in the Council of Europe and the Euronest Parliamentary Assembly in which these states forge closer political and economic ties with the European Union.