This article gives an overview of socialism in the Netherlands, including communism and social democracy. It is limited to communist, socialist, and social-democratic parties with substantial support, mainly proved by having had a representation in parliament. The sign ⇒ means a reference to another party in that scheme.
Socialism came relatively late to the Netherlands, because of its slow industrialization. In the 1860s a socialist movement began to develop. Although the socialists were aided by the foundation of the First International and of the first Dutch trade unions, united in the Algemeen Nederlands Werklieden Vereniging, a socialist party was not founded until 1881, when the Social Democratic League was founded. The slow industrialization was reflected in the support base of the first socialist parties. It wasn't the urban proletariat which supported them most, instead it were agricultural workers, who were the first to support the League.
Before the First World War, the socialist movement saw two major splits: in 1894 between revolutionary anarchists and parliament-oriented socialists. The latter left the League to found the Social-Democratic Workers' Party, while the former kept control of the SDB, which was soon banned by the government. The second split was between a revolutionary Marxist opposition and a reformist-revisionist establishment. In 1907 the opposition group left the SDAP to found the Social-Democratic Party, which would become the Communist Party of the Netherlands (CPN) after the Russian Revolution. This was one of the first splits between reformists and revolutionaries within the European labour movement. Both the revolutionaries and the reformists have their own labour unions, the reformist Nederlands Verbond van Vakverenigingen and the anarcho-syndicalist Nationaal Arbeidssecretariaat.