Karl Rudolf Heinze (22 July 1865 – 26 May 1928) was a German jurist and politician. During the Weimar Republic, as a member of the right-of-centre German People's Party (DVP) he was Vice-Chancellor of Germany and Minister of Justice in 1920/21 in the cabinet of Konstantin Fehrenbach and from 1922 to 1923 again Minister of Justice under Wilhelm Cuno.
Karl Rudolf Heinze was born on 22 July 1865 in Oldenburg in what was then the Grand Duchy of Oldenburg as the son of Max Heinze, a professor of the history of philosophy. He attended the Gymnasium in Basel and Leipzig from 1874-81. Following the Abitur he studied at Tübingen, Heidelberg, Berlin and Leipzig, where he was awarded the doctor juris in 1887. After voluntarily serving for one year in the military in 1888, Heinze worked from 1898-1912 in the judicial service of Saxony, at the end in the position of Landgerichtsdirektor. He then joined the Reichsanwaltschaft , the prosecution at the Reichsgericht in Leipzig. In 1914, he became a Reichsgerichtsrat.
In 1900, Heinze married Anna (1863-1948) née Hotop. They had three sons and a daughter.
Heinze began his political career in 1899, when he became a Stadtverordneter (member of the city council) at Leipzig. From 1903 he was an unsalaried Stadtrat (member of the city government) in Dresden. From 1907 to 1912, he held a seat in the Reichstag for the National Liberal Party where he was a member of the party's right wing. In 1915-16, Heinze was a member of the Landtag (diet) of the Kingdom of Saxony. On account of personal contacts to Turkey, Heinze then was appointed Undersecretary of State at the Ministry of Justice of the Ottoman Empire in Constantinople. He remained there until the summer of 1918.