A regulation is a legal act of the European Union which becomes immediately enforceable as law in all member states simultaneously. Regulations can be distinguished from directives which, at least in principle, need to be transposed into national law. Regulations can be adopted by means of a variety of legislative procedures depending on their subject matter. Despite their name, Regulations are primary legislation rather than regulatory delegated legislation; as such, they are often described as "Acts" (e.g. the Digital Services Act).

The description of regulations can be found in Article 288 of the Treaty on the Functioning of the European Union (formerly Article 249 TEC).

Article 288

To exercise the Union's competences, the institutions shall adopt regulations, directives, decisions, recommendations and opinions.

A regulation shall have general application. It shall be binding in its entirety and directly applicable in all Member States.

A directive shall be binding, as to the result to be achieved, upon each Member State to which it is addressed, but shall leave to the national authorities the choice of form and methods.

A decision shall be binding in its entirety upon those to whom it is addressed.

Recommendations and opinions shall have no binding force.