Dietrich Klagges (German pronunciation: [ˈdiːtʁɪç ˈklaɡəs]) (1 February 1891 in Herringsen, now part of Bad Sassendorf – 12 November 1971 in Bad Harzburg) was a National Socialist politician and from 1933 to 1945 the appointed premier (Ministerpräsident) of the now abolished state of Braunschweig. He also went by the pseudonym Rudolf Berg.
Klagges was the youngest of a forest ranger's seven children. He underwent training as a Volksschule teacher at the teaching seminary at Soest and worked as such beginning in 1911 in Harpen near Bochum. During the First World War he was badly wounded and therefore discharged from army service by 1916. In 1918 he joined the German National People's Party and stayed with the party until 1924. After the First World War he became a Realschule teacher in Wilster in Holstein. After leaving the German National People's Party, Klagge was for a short time a member of the extreme rightwing German Nationalist Freedom Party (Deutschvölkische Freiheitspartei), which had been founded late in 1922. He soon left it, eventually joining the NSDAP in 1925. From 1926 until 1930 he worked as a deputy headmaster at a middle school in Benneckenstein (now in Saxony-Anhalt), where from 1928 to 1930 he also served as the local Nazi Ortsgruppe leader. Because of his membership in the Party, he was dismissed from the Prussian school service and furthermore stripped of his pension. In the same year he first rose to prominence in Braunschweig, where he busied himself as a Nazi propaganda speechmaker.