Ernst Tengelmann was a German entrepreneur.
From 1912 he was Director-General of the Essener Steinkohlenbergwerke AG and CEO of Gelsenkirchener Bergwerks-AG. In addition to Carl Hold and Gustav Knepper he was one of the most influential mining figures in 1930s Ruhr Valley.

In the 1920s Tengelmann was an active member of the German People's Party

German People's Party

The German People's Party was a national liberal party in Weimar Germany and a successor to the National Liberal Party of the German Empire.-Ideology:...

, but in 1930 he joined the Nazi party and participated in the Secret Meeting of 20 February 1933

Secret Meeting of 20 February 1933

The Secret Meeting of 20 February 1933 was a secret meeting between Adolf Hitler and 20 to 25 industrialists at the official residence of Hermann Göring in the Reichstag Presidential Palace aimed at financing the election campaign of the Nazi Party.The German elections were to be held on 5 March...

where he gave the party considerable financial support. His sons, Walter and Wilhelm also worked actively for the Nazi party.