The Gotha Program (German: Gothaer Programm) was the party platform adopted by what would become the Social Democratic Party of Germany (SPD) at its initial conference, held in the city of Gotha from 22 to 27 May 1875. Written by Wilhelm Liebknecht, the program was the result of a compromise between the two founding factions of the party: the Marxist-influenced Social Democratic Workers' Party (SDAP), known as the "Eisenachers", and the General German Workers' Association (ADAV), founded by Ferdinand Lassalle.

The program called for universal suffrage, freedom of association, limits on the working day, and other laws protecting the rights and health of workers. While its immediate demands were radically democratic for the time, the Gotha Program was strongly influenced by Lassalleanism, declaring the party's intention to pursue its goals "by every legal means" and calling for the establishment of state-aided producer co-operatives.

This deference to Lassallean ideas drew sharp criticism from Karl Marx, an opponent of Lassalle who had been living in London. In an 1875 letter later published as the Critique of the Gotha Program, Marx attacked the program for a variety of perceived flaws. Marx took issue with what he saw as its theoretical vagueness, its lack of a revolutionary and class-based analysis, its embrace of bourgeois democratic ideals, and its concessions to the power of the state. The Gotha Program served the unified party for 16 years. During the period of Anti-Socialist Laws from 1878 to 1890, the party became more explicitly revolutionary and Marxist in its outlook. In 1891, following the repeal of the laws and the publication of Marx's critique, the party adopted the more consistently Marxist Erfurt Program.

In the 1860s and early 1870s, the German socialist movement consisted of two main rival parties. The first, the General German Workers' Association (ADAV), was founded by Ferdinand Lassalle in 1863. Lassalle's program aimed to achieve socialism through the introduction of democracy, primarily by establishing producer co-operatives with state support. The second party was the Social Democratic Workers' Party (SDAP), founded in 1869 by Wilhelm Liebknecht, a disciple of Karl Marx, and the young activist August Bebel. The party's program, known as the Eisenach Program, was more explicitly Marxist and revolutionary, distinguishing it from the Lassallean ADAV.

After the unification of Germany in 1871, the old political divisions over unification became less relevant, and the two parties found common cause in defending the living standards of the working class against rising prices. This shared interest created an opening for a formal merger. Governmental repression of both parties following the unification of Germany also pushed them towards a merger. Leaders of the two factions held preliminary conferences in December 1874 and February 1875, where they produced a draft program for a unified party. The formal unity congress, where a unity commission representing both parties met, was held in Gotha from 22 to 27 May 1875. For the Eisenach leaders, the goal of achieving unity in the German labour movement for the practical pursuit of democratic objectives took precedence over strict adherence to Marxist doctrine. Marx’s primary grievance with the draft was its inclusion of Lassallean concepts—specifically the "iron law of wages" and the demand for state-aided producer cooperatives—which he viewed as a capitulation to the Prussian state and a misunderstanding of the capitalist mode of production.

The conference in Gotha produced both a new, unified party—the Socialist Workers' Party of Germany [de] (SAPD)—and a new party platform. The Gotha Program has been described as an "awkward synthesis" of the traditional ideas of the Lassallean and Eisenacher factions. It was, in the words of historian Carl Schorske, "more strongly influenced by Lassalle than by Marx."

The program, written by Liebknecht, synthesized ideas from both factions. The political demands reflected the Eisenacher tradition, calling for a "Free State" (freier Staat) and demanding universal, equal, and direct suffrage; direct legislation by the people; and full civil liberties. The economic planks were strongly Lassallean, calling for the creation of state-financed producer co-operatives to abolish the iron law of wages and declaring that, in contrast to the working class, "all other classes are but one reactionary mass"; an explicit link to the trade union movement was not included. As a concession to the Eisenachers, Liebknecht did manage to add a stronger commitment to working-class internationalism than had appeared in the initial draft. A key plank that reflected the influence of the Lassallean faction was the pledge that the party would pursue its aims "with every legal means".

The program was sent to Karl Marx in London for his review before its adoption. Marx responded with "intense annoyance" and wrote a lengthy letter, later known as the Critique of the Gotha Program, detailing his objections. In it, he argued that the program was "confused, state-socialistic," and theoretically inadequate, and that it had made too many concessions to Lassalleanism. He contended that it "contained none of his analysis of economic development, no word of revolution, and no clear indication of the class character of the state".