Lothar-Günther Buchheim was a German painter, graphic artist, collector, author, and publisher best known for his novel Das Boot and his extensive collection of German Expressionist art. Alongside his literary career, he produced paintings, drawings, and graphic works, while also becoming one of Germany's most important private collectors of twentieth-century art.

Born in Weimar in 1918, Buchheim showed an early interest in drawing and held his first exhibition at the age of fifteen. He studied art in Dresden and Munich before volunteering for the German Navy during the Second World War. As a war correspondent, he served aboard minesweepers, destroyers, and submarines, documenting the conflict through photographs, sketches, and written reports. His experiences later became the basis for Das Boot (1973), one of the best-known anti-war novels of the twentieth century.

After the war, Buchheim worked as an artist, publisher, gallery owner, and art dealer. He published books on artists including Georges Braque, Max Beckmann, Pablo Picasso, and Otto Mueller, while building an exceptional collection of German and French Expressionist art. His collection included works by Ernst Ludwig Kirchner, Emil Nolde, Wassily Kandinsky, Paul Klee, Franz Marc, Gabriele Münter, and Alexej von Jawlensky.

Alongside his writing and collecting, Buchheim continued to paint and create graphic works throughout his career. His paintings often reflected the expressive colour and energy of German Expressionism, while his later museum displays combined artworks with found objects, sculptures, and installations that blurred the line between exhibition and environment.

In 2001, Buchheim opened the Museum der Phantasie on Lake Starnberg in Bavaria to house his collection. Today, the museum remains one of Germany's most important collections of German Expressionist art. Lothar-Günther Buchheim died in 2007.