The Socialist Workers Party of Greece (SEK) is an affiliate of the International Socialist Tendency (IST). It is probably the largest section of the IST other than the Socialist Workers Party of Britain and its central leaders Panos Garganos and Maria Stylou play a major role within it.

It originated among a group of exiled Greek students stuying in London after the 1967 Colonels Coup in greece. They were then influenced by Maoist ideas and organised themselves as the Socialist Revolution Organisation (OSE). While in London they developed relations with the International Socialists led by Tony Cliff and generally adopted the views associated with the IS tradition of Trotskyism. However on returning to Greece their connection with the IS was abandoned.

In the early 1980s the OSE again develped close links with the IS, now known as the SWP, and grew fairly rapidly. Having grown they changed their name to the Socialist Workers Party. However they suffered a split in 2001 when a minority faction left to form the Internationalist Workers Left (DEA) group.