A euromyth is a exaggerated or invented story about the European Union (EU) and the activities of its institutions, such as purportedly nonsensical EU legislation.

Conversely, the same term has been applied by Eurosceptics to purportedly misleading or exaggerated claims by the European Commission, and some assert that the term (in the former sense) is falsely applied to true stories.

Debate as to whether a particular claim is true sometimes continues long after the original story appeared. On occasions, Euromyths may arise when the actions of a different European organisation, such as the Council of Europe, are erroneously attributed to the EU.

In 2000, the British government announced a policy of publicly rebutting such myths and accused journalists of failing in their mission to inform. Accusations of distorted or untruthful reporting are most commonly directed at conservative and Eurosceptic sections of the British media. Stories can present the European civil service as drafting rules that "defy common sense". Examples cited as Euromyths include stories about rules banning mince pies, prawn cocktail crisps, curved bananas and mushy peas. Others include a story that English fish and chips shops would be forced to use Latin names for their fish (The Sun, 5 September 2001), quoted in that double-decker buses would be banned (The Times, 9 April 1998), that barmaids would have to cover up their cleavage.

In some cases, Euromyth stories have been traced to deliberate attempts by lobbyists to influence actions by the European bureaucracy, such as the level of customs duties for particular products. EU officials have also claimed that many such stories result from unclear or misunderstood information on complicated policies, and are claimed to have seized on minor errors in stories as evidence that they are entirely fictional.