Carl Theodor Johann Ulrich (28 January 1853 – 12 April 1933) was a German politician of the Social Democratic Party (SPD) who served as the first State-President of the People's State of Hesse from 1918 to 1928. He was a member of the Hessian state parliament for 46 continuous years from 1885 to 1931, making him the longest-serving legislator in German history. He also served in the Reichstag for 36 years between 1890 and 1930.