Karl Ruben

Karl Ruben (4 August 1903 – 28 October 1938) was a Danish chess master.

He won a match against Johannes Pedersen (1.5–0.5) at Aalborg 1927, tied for 2nd-3rd in Danish Championship at Vordingborg 1927 (Erik Andersen won), shared 2nd at Copenhagen 1927 (Politiken, Géza Maróczy won), tied for 5-6th at Copenhagen 1928 (Aron Nimzowitsch won), tied for 7-9th at Svendborg 1930 (DEN-ch, Andersen won), and won a simultan game against Alexander Alekhine at Copenhagen 1930.

Ruben played four times for Denmark in Chess Olympiads in 1927, 1928, 1930, 1931, and won team silver medal at London 1927.