R (Factortame Ltd) v Secretary of State for Transport was a judicial review case taken against the United Kingdom government by a company of Spanish fishermen who claimed that the United Kingdom had breached European Union law (then Community Law) by requiring ships to have a majority of British owners if they were to be registered in the UK. The case produced a number of significant judgements on British constitutional law, and was the first time that courts held that they had power to restrain the application of an Act of Parliament pending trial and ultimately to disapply that Act when it was found to be contrary to EU law.

The litigation was lengthy, and is typically divided into five main stages:

• Factortame I, where the High Court and then the House of Lords (as Supreme Court) both made a reference to the European Court of Justice on the legality of the Merchant Shipping Act 1988's ("MSA") requirement for UK fishing vessels to be 75% UK owned. After the ECJ confirmed the incompatibility of the Act with EU law, Factortame saw the House of Lords confirm the primacy of EU law over national law in the areas where the EU has competence because of the UK acceding to the EU treaties.
• Factortame II, where the ECJ held that the provisions of the MSA were required to be disapplied by the UK courts if they contravened EU law.
• Factortame III, where the ECJ held that a member state could be liable for damages in an action by the European Commission for breach of EU law.
• Factortame IV, where the House of Lords ruled that damages could be awarded against a member state like the UK for losses suffered by private parties under the Francovich v Italy principle, that wrongs by violation of a public body generate a private law claim from anybody who has suffered a directly connected loss (also known as the doctrine of state liability).
• Factortame V, holding that claims after 1996 were statute-barred, since claims against a member state were like other claims in tort under the Limitation Act 1980.