The Maastricht Rebels were British Members of Parliament (MPs) belonging to the then governing Conservative Party who refused to support the government of Prime Minister John Major in a series of votes in the House of Commons on the issue of the implementation of the Maastricht Treaty in British law.

The Treaty on European Union, commonly known as the Maastricht Treaty, is the foundation treaty of the European Union (EU). Concluded in 1992 between the then-twelve member states of the European Communities, it announced "a new stage in the process of European integration" chiefly in provisions for a shared European citizenship, for the eventual introduction of a single currency, and for common foreign and security policies, and a number of changes to the European institutions and their decision taking procedures, not least a strengthening of the powers of the European Parliament and more majority voting on the Council of Ministers. Although these were seen by many to presage a "federal Europe", key areas remained inter-governmental with national governments collectively taking key decisions. This constitutional debate continued through the negotiation of subsequent treaties, culminating in the 2007 Treaty of Lisbon.