Der Blaue Reiter (The Blue Rider) was a group of artists from the Neue Künstlervereinigung München in Munich, Germany. The group was founded by a number of Russian emigrants, including Wassily Kandinsky, Alexej von Jawlensky, Marianne von Werefkin, and native German artists, such as Franz Marc, August Macke and Gabriele Münter. Der Blaue Reiter was a movement lasting from 1911 to 1914, fundamental to Expressionism, along with Die Brücke which was founded in 1905.

Wassily Kandinsky, Franz Marc, August Macke, Alexej von Jawlensky, Marianne von Werefkin, Gabriele Münter, Lyonel Feininger, Albert Bloch and others formed the group in response to the rejection of Kandinsky's painting Last Judgement from an exhibition. Der Blaue Reiter lacked an artistic manifesto, but it was centered around Kandinsky and Marc. Paul Klee was also involved.

The name of the movement is the title of a painting that Kandinsky created in 1903, but it is unclear whether it is the origin of the name of the movement, as Professor Klaus Lankheit learned that the title of the painting had been overwritten. Kandinsky wrote 20 year later that the name is derived from Marc's enthusiasm for horses and Kandinsky's love of riders, combined with both love of the color blue. For Kandinsky, blue is the colour of spirituality: the darker the blue, the more it awakens human desire for the eternal (see his 1911 book On the Spiritual in Art).