The official publication of record for the European Union. EU legislation can only become legally binding once it has been published in the Official Journal (EUR-Lex: Official Journal).

The Official Journal (OJ) is published Monday to Friday inclusive, and on Saturdays, Sundays and public holidays only in urgent cases. The OJ is published in all the official EU languages (see Europa: Multilingualism).

Since 1 July 2013, the electronic edition of the OJ published on EUR-Lex is authentic and produces legal effects (Council Regulation (EU) 216/2013). The paper version no longer has any legal value, except when OJ cannot be published online due to unforeseen disruption to IT systems.

The Official Journal consists of two main series:

There is also a subseries CA, which has the same number as the C series published on the same day (for example, C019A). It contains calls for expressions of interest, vacancy notices and so on. CA editions may appear in one, several or all official languages.

From 1 January 2016, a new subseries, LI and CI, was introduced to allow for greater flexibility in the event of a change in the planned content (for example, L015I).