[1] Full members status is held to the European Youth Forum (YFJ) which operates within the Council of Europe and European Union areas and works closely with both these bodies.

[2] YES was founded as the European Community Organisation of Socialist Youth (ECOSY) in November 1992 in Oegstgeest/The Hague.

The preparatory committee consisted of Philip Cordery (MJS, France), Joris Jurriëns (JS-PvdA, Netherlands), Jens Geier (Jusos, Germany), Giustina Magistretti (Italy), and Pascal Smet (Belgium).

In particular, the Austrians and the Swedes promoted an all-European organisation, including non-EU members.

The organisation's name was changed to Young European Socialists (YES) at the 11th Congress in Bommersvik in 2013.