Elections to the European Parliament will be held around the month of June 2009 in the 27 member states of the European Union, using varying election days according to local custom. 496 million Union citizens will elect 736 MEPs by proportional representation, topping the 2004 election which was the biggest trans-national election in history.

It could potentially be the first election to take place under the expected Treaty of Lisbon, increasing the power of the Parliament and relevance of the election.