Fritz Mannheimer (19 September 1890 – 9 August 1939) was a German-born and, from 1936, Dutch banker and art collector who was the director of the Amsterdam branch of the Berlin-based investment bank Mendelssohn & Co. that was for some time the main supporter of the Dutch capital market. Known as the "King of Flying Capital", he was one of the main organisers of credit for post-war Germany. His international financial work brought him recognition, such as being awarded Grand Officer of the Légion d'honneur. His collection was bought by Hitler in 1941, but it was returned to the Netherlands after the war.