The German Democratic Party was a liberal political party in the Weimar Republic, considered centrist or centre-left. Along with the right-liberal German People's Party, it represented political liberalism in Germany between 1918 and 1933. It was formed in 1918 from the Progressive People's Party and the liberal wing of the National Liberal Party, both of which had been active in the German Empire.

The German People's Party was a conservative-liberal political party during the Weimar Republic that was the successor to the National Liberal Party of the German Empire. Along with the left-liberal German Democratic Party (DDP), it represented political liberalism in Germany between 1918 and 1933.