2009 Basque regional election

The 2009 Basque regional election was held on Sunday, 1 March 2009, to elect the 9th Parliament of the Basque Autonomous Community. All 75 seats in the Parliament were up for election. The election was held simultaneously with a regional election in Galicia. It would be the first time that the elections for two of the Spanish "historical regions"—namely, those comprising Andalusia, Catalonia, Galicia and the Basque Country itself—were held simultaneously. This would evolve into an unwritten convention in subsequent years, with Basque and Galician elections being held concurrently in 2012, 2016 and 2020.

The 2009 Basque election was the first one to be held without any major electoral candidacy from the abertzale left, after their previous iterations—the Communist Party of the Basque Homelands (PCTV/EHAK) and Basque Nationalist Action (ANV)—had been outlawed in September 2008 because of their reported ties to ETA and the outlawed Batasuna party. In early February 2009, two political groupings formed by abertzale left members to contest the election, Demokrazia Hiru Milioi (D3M) and Askatasuna ("Freedom"), were barred from contesting the election by both the Supreme Court and the Constitutional Court. In response, the abertzale left asked their voters to cast invalid ballots, both in protest to the court rulings and seeking to prevent tactical voting in favour of either Lehendakari Juan José Ibarretxe's Basque Nationalist Party (PNV) or Eusko Alkartasuna (EA).

The election resulted in an upset, as Basque nationalist parties lost their parliamentary majority for the first time in 30 years, paving the way for a non-PNV led government. The Socialist Party of the Basque Country–Basque Country Left (PSE–EE) under Patxi López gained seven seats to command a 25-strong caucus, the best historical showing of the party in a Basque regional election. The People's Party (PP), which had switched leaders less than a year before the election as former leader María San Gil quit over disagreements with the national leadership of Mariano Rajoy, had a net loss of two seats from 2005. The new Union, Progress and Democracy (UPyD) party, founded in 2007 by former PSOE member and regional minister Rosa Díez was able to achieve a breakthrough in Álava and have its regional candidate Gorka Maneiro elected. Meanwhile, PNV's previous coalition partners, Eusko Alkartasuna (EA) and Ezker Batua (EB), suffered a harsh electoral downturn with both their leaders losing their seats and resigning in the aftermath of the election.

The PSE formed a minority government with López as the first non-PNV lehendakari since 1979 through a confidence and supply agreement with the PP. While both parties had established an uneasy alliance in the Basque Country since the late 1990s despite their overall national rivalry, this would constitute the most relevant agreement reached between both parties at any level of administration.