Otto Stangl (Dachau, October 9, 1915 - Munich, July 20, 1990) was a German gallery owner, art dealer and art collector.
With his wife Etta Stangl they founded in 1947 in Munich the Moderne Galerie Etta und Otto Stangl, an important gallerie of the avant-garde after the Second World War in Germany.
Their influence on the transmission of contemporary art played an important role in the rehabilitation of the so-called degenerate art of the Third Reich (mainly Blauer Reiter, expressionism, classical modern art).
Etta and Otto Stangl were also involved in establishing the Franz Marc Museum in Kochel am See, which opened in 1986.