The Treaty on European Union (2007) is one of the primary Treaties of the European Union, alongside the Treaty on the Functioning of the European Union (TFEU). The TEU forms the basis of EU law, by setting out general principles of the EU's purpose, the governance of its central institutions, as well as the rules on external, foreign and security policy.

The Treaties of the European Union are a set of international treaties between the European Union (EU) member states which sets out the EU's constitutional basis. They establish the various EU institutions together with their remit, procedures and objectives. The EU can only act within the competences granted to it through these treaties and amendment to the treaties requires the agreement and ratification of every single signatory.