The first homosexual movement was a socio-political movement which thrived in Germany from the late nineteenth century until 1933. The movement began in Germany because of a confluence of factors, including the criminalization of sex between men and the country's relatively lax censorship. German writers in the mid-nineteenth century coined the word homosexual and criticized its criminalization. In 1897, Magnus Hirschfeld founded the world's first homosexual organization, the Scientific-Humanitarian Committee, whose aim was to use science to improve public tolerance of homosexuality and repeal Paragraph 175. During the German Empire, the movement was restricted to an educated elite, but it greatly expanded in the aftermath of World War I and the German Revolution.

Before 1933, male homosexual acts were illegal in Germany under Paragraph 175 of the German Criminal Code. The law was not consistently enforced, however, and a thriving gay culture existed in major German cities. After the Nazi takeover in 1933, the first homosexual movement's infrastructure of clubs, organizations, and publications was shut down. After the Röhm purge in 1934, persecuting homosexuals became a priority of the Nazi police state. A 1935 revision of Paragraph 175 made it easier to bring criminal charges for homosexual acts, leading to a large increase in arrests and convictions. Persecution peaked in the years prior to World War II and was extended to areas annexed by Germany, including Austria, the Czech lands, and Alsace–Lorraine.