The 2019 European Parliament election was the United Kingdom's component of the 2019 European Parliament election. It was held on Thursday 23 May 2019 and the results announced on Sunday 26 and Monday 27 May 2019, after all the other EU countries had voted. This was the United Kingdom's final participation in a European Parliament election before leaving the European Union on 31 January 2020, and was also the last election to be held under the provisions of the European Parliamentary Elections Act 2002 before its repeal under the European Union (Withdrawal) Act 2018.

The 2019 European Parliament election was held between 23 and 26 May 2019, the ninth parliamentary election since the first direct elections in 1979. A total of 751 Members of the European Parliament (MEPs) represent more than 512 million people from 28 member states. In February 2018, the European Parliament had voted to decrease the number of MEPs from 751 to 705 if the United Kingdom were to withdraw from the European Union on 29 March 2019. However, the United Kingdom participated alongside other EU member states after an extension of Article 50 to 31 October 2019; therefore, the allocation of seats between the member states and the total number of seats remained as it had been in 2014. The Ninth European Parliament had its first plenary session on 2 July 2019.