The Anti-Socialist Laws or Socialist Laws (German: Sozialistengesetze; officially Gesetz gegen die gemeingefährlichen Bestrebungen der Sozialdemokratie, approximately "Law against the public danger of Social Democratic endeavours") were a series of acts, the first of which was passed on October 19, 1878 by the German Reichstag lasting till March 31, 1881, and extended 4 times (May 1880, May 1884, April 1886 and February 1888). The legislation was passed after two failed attempts to assassinate Kaiser Wilhelm I by the radicals Max Hödel and Dr. Karl Nobiling; it was meant to curb the growing strength of the Social Democratic Party (SPD, named SAP at the time), which was blamed for influencing the assassins.

Although the law did not ban the SPD directly, it aimed to cripple the organization through various means. The banning of any group or meeting of whose aims were to spread social democratic principles, the outlawing of trade unions and the closing of 45 newspapers are examples of suppression. The party circumvented these measures by having its candidates run as ostensible independents, by relocating publications outside of Germany and by spreading Social Democratic views as verbatim publications of Reichstag speeches, which were privileged speech with regard to censorship.