Henri Mathias Berthelot (7 December 1861 – 29 January 1931) was a French general during World War I. He held an important staff position under Joseph Joffre, the French commander-in-chief, at the First Battle of the Marne, before later commanding a corps in the front line. In 1917 he helped to rebuild the Romanian Army following its disastrous defeat the previous autumn, then in summer 1918 he commanded French Fifth Army at the Second Battle of the Marne, with some British and Italian troops under his command. In the final days of the war he again returned to Romania, helping fight the Hungarians during the Hungarian–Romanian War and then briefly commanded French intervention forces in southern Russia in the Russian Civil War, fighting the Russian Bolsheviks in Bessarabia (1918).