A referendum on joining the European Union was held in the Czech Republic on 13 and 14 June 2003.

The proposal was supported by 77% of voters, with a turnout of 55%.

The Czech Republic joined the EU on 1 May 2004.

The table lists the political parties which were represented in the parliament at the time of the referendum.

Opinion polls in the run-up to the referendum showed support for joining from 63% to over 70%, with the highest support among younger, wealthier and better educated people.