The Estonian United Left Party (Estonian: Eestimaa Ühendatud Vasakpartei) is a political party in Estonia undergoing reformation.
 Through the Estonian Left Party, the party, founded in 2008, is the direct descendant of the Communist Party of Estonia, the former ruling party of Estonia during the Estonian Soviet Socialist Republic period. Since 2004, through the Estonian Left Party, the party is a founding member  of the Party of the European Left.
 The party started self-reforming in 2023 to be a more youth-oriented "pro-Estonian, modern and Nordic left party", intending to de jure rebrand as Vasakpoolsed (lit. 'the Left'  or 'the Left-Wingers') by early 2024.
 On 28 June 2008, the Estonian Left Party (a party comprising most of the remnants of the post-1990 Communist Party of Estonia) and the Constitution Party (one of two parties representing the Russian minority in Estonia) merged to form the Estonian United Left Party (Eestimaa Ühendatud Vasakpartei). Despite the party's professed adherence to a left-wing direction, some observers and journalists have noted and claimed that the party is perceived to be more interested in catering to Russian minority politics and has been relatively marginal in Estonian politics. In particular, party chairman Mstislav Rusakov made a comment about the party's apparent obscurity for an interview for Eesti Rahvusringhääling: "The problem is to convey this information to people, because, as I already said, go out into the street, ask: "The United Left Party ...?", they will tell you: "What is this?". Meanwhile, in an opinion article for the online Russian-language edition of Postimees, Valery Saïkovski asserts that the party is primarily relevant for Russian minority politics purposes.
 In 2018, there were posters in Tallinn allegedly from the EÜVP that endorsed Pavel Grudinin, the presidential candidate from the Communist Party of the Russian Federation running in the 2018 Russian presidential election. However, the party has denied that they are responsible for these posters, and the Russian Embassy in Estonia called them "low quality craft".
 For the 2023 Estonian parliamentary elections, the party ran informally with members of Together who joined the party due to failing to register their own before the registration deadline. The Estonian United Left Party earned a record high of 2.4% votes in the election and thus qualified for state funding for the very first time, shocking many pundits. Most of the votes earned by the party came from people voters of Together founder Aivo Peterson.
 In August 2023, then-party leader Igor Rosenfeld was removed by court order and replaced with barrister Keijo Lindeberg as a substitute member of the board until the next party board elections. In September 2023, the party announced its intention to rebrand as Left-Wingers or the Left (Estonian: Vasakpoolsed) by early 2024, launching a new website and social media presence after being informed by the court that law requires the former to exist for every single party. The party's Twitter account was temporarily restricted. The party is set to hold a general meeting to elect new leadership on 3 February 2024.
 Then-party leader Igor Rosenfeld complained about the party having been taken over by "Russian conservatives" between 2018 and 2022. He also referred to Russia as an empire and said the party supports an independent Ukraine as opposed to one under Russia, adding that it should be "more neutral" and "less agressive towards Russia". He blames the "Russian elite" and "radicals on both sides" for the invasion of Ukraine, claiming that the "banderite" "Ukrainian radicals" took power in 2014 and that the Liberal Democratic Party of Russia and Rodina are war parties. He also labelled his own party Eurocommunist. After the 2023 parliamentary election, he referred to the Revolution of Dignity as a coup and ruled out further cooperation with Together if they are prosecuted, stating that "we will not be able to cooperate with those people who will be recognized as violating the law" and "we do not want to violate the laws of the Republic of Estonia in any way".
 He also mentioned that the party doesn't support the Russian world theory promoted by "radical parts" of Together. He also claimed that a member of Parempoolsed had been appointed to replace him on the party board by the Harju County Court following the court's move to appoint barrister Keijo Lindeberg as the sole substitute member of the board after his removal. Rosenfeld commented on the move as a "right-wing dictatorship" attack on the party, tying them together with Together and claiming that there was an attempt to liquidate the party, adding that there's a "special Baltic order in the EU" that is "Francoist" and "not a democracy". He was eventually replaced with Lindeberg who began reforming the party.
 Lindeberg said that "the party does not question Estonia's current foreign and security policy course", preferring to focus on domestic topics to appeal to the "ordinary worker" and the "less well-off". He added that the party's target voters would be "pro-Estonian" left-wing youth without a party preference as well as voters of the Social Democrats, Centre Party and the Greens. One of the party's new members, former Social Democrats youth organization vice president Robert Kiisler said that he and "like-minded people are trying to create a pro-Estonian, modern and Nordic left party from the basis of the United Left Party, such as the Left Alliance in Finland or the Red-Green Alliance in Denmark".
 On December 18, the party put out a long policy statement, in which the party denounced its cooperation with Together in the 2023 parliamentary election, announced that all contacts had been since cut and that the party has no tolerance for pro-Kremlin viewpoints, including spread of Kremlin narratives about the Russian invasion of Ukraine or support for Vladimir Putin's regime, adding that anyone with such views can't be a member of the party. In terms of ideology, it announced support for progressive income tax, taxation of corporate profits, inheritance tax, additional social benefits for the needy, establishing fair wages for teachers, police officers, firefighters, and providing additional social security. The party reiterated that it agrees with Estonia's existing foreign policy choices, including EU and NATO membership, and expresses support for Ukraine against Russia's aggression. Moreover, the party announced that its main target demographic would be the youth, especially those without a party preference. On social issues, the  party described itself as "neither liberal nor conservative".