Central Organisation of the Workers of Sweden (in Swedish: Sveriges Arbetares Centralorganisation, SAC - Syndikalisterna) is a syndicalist trade union federation in Sweden. Unlike other Swedish unions, SAC organises people from all occupations and industries in one single federation, including the unemployed, students, and the retired. SAC also publishes the weekly newspaper Arbetaren ("the Worker"), owns the publishing house Federativs and runs the unemployment fund Sveriges Arbetares Arbetslöshetskassa (SAAK).

The SAC's long-term goal is to realize libertarian socialism, a society without classes and hierarchies, where the means of production are owned commonly and administrated by the workers: in effect, abolition of capitalism, wage slavery, and sexism. As such, SAC is an anti-sexist and anti-militarist organisation, which in 1998 also became the first Swedish openly feminist trade union. Short-term goals are improved salaries and working environments. It frequently cooperates with other libertarian socialist organisations, such as the Swedish Anarcho-syndicalist Youth Federation (SUF), although SUF is not a part of SAC.

The SAC was founded in 1910 by disgruntled members of the Social Democratic LO trade union central after its failure to carry out a Swedish General Strike, and were joined by large sections of the youth wing of the Swedish Social Democratic Party, who also had come under the influence of the revolutionary syndicalism of the French Confédération Générale du Travail. In 1922 the newly formed union confederation also became founding member organisation of the anarcho-syndicalist International Workers' Association; however, conflicts erupted between the organisations in the 1950s as SAC set up a state-supported unemployment fund, something which the IWA regarded as state collaboration and reformist. From 1956 and onwards the SAC stopped paying its membership fees to the IWA, effectively letting its affiliation lapse. Today the SAC is affiliated with the Red and Black Coordination, an international network of revolutionary syndicalist and anarcho-syndicalist unions.

The traditional strongholds of the SAC were primarily in the forestry, mining, and construction industries. Today the majority of the union's members are employed in the public sector, often working in sectors like railway and public transports, healthcare, and education, but many of the members can also be found in the restaurant, information technology, and logistics industries.