Wilhelm Külz (18 February 1875 – 10 April 1948) was a German liberal politician of the National Liberal Party, the German Democratic Party (DDP) and later the Liberal Democratic Party of Germany (LDPD).
He held public office both in the German Empire and in the Weimar Republic.
In 1926, he served as interior minister of Germany in the cabinets of chancellors Hans Luther and Wilhelm Marx.