Under röd flagg (Swedish for 'Under red flag') was a weekly magazine published in Sweden in 1891 by Hinke Bergegren. Bergegren acted as the editor and publisher of the magazine. Nine issues were published from March to June 1891. Under röd flagg sought to bring together writers from the political peripheries of the Social-Democratic Party. Articles in the publication contained Marxist, anarchist and anarchist communist ideas. Under röd flagg was the first periodical to introduce a detailed account of anarchist thought in Sweden, for example through texts of Peter Kropotkin, Leo Tolstoy, Élisée Reclus and Swedish anarchists.