Born at Lesneven (Finistère), he graduated from Saint-Cyr in 1900 and joined the colonial infantry. During World War I he served in the Middle Eastern theatre. He was chief of staff of operations of the Allied Expeditionary Force. In 1918 he participated in the development of General Louis Franchet d'Espèrey's offensive against German and Bulgarian forces which would lead to Allied victory and the signing of the Armistice of Mudros in October 1918.
In 1933, Huntziger was named commander-in-chief of the troops in the French Mandate of Syria. He participated in the negotiations for the cession of the Sanjak of Alexandretta, then part of French Syria, to Turkey. He joined the Superior Council of War in 1938.
During World War II, in 1939–1940, he initially commanded the Second French Army, then the Fourth Army Group in the Ardennes. He fought in the Battle of France with the Second Army. On 16 June 1940 Premier Philippe Pétain's new Cabinet decided upon an armistice. The armistice negotiations were led, on the French side, by Huntziger. 
After the 25 June armistice, Huntziger became the Vichy government's commander-in-chief of the land forces. He became Minister of Defence on 6 September 1940, serving until 11 August 1941. He was one of the signatories of the anti-Semitic Statute on Jews of 3 October 1940 (excluding nine Jewish generals from the army) alongside Philippe Pétain, Pierre Laval, Raphaël Alibert, Marcel Peyrouton, Paul Baudouin, Yves Bouthillier, and François Darlan.
He died on 11 November 1941, when his plane crashed near Le Vigan, Gard. He had been on an inspection tour in North Africa, and tried to land at Vichy Airport in bad visibility, and with obsolete radio equipment. His funeral was on 15 November 1941 at the cathedral of Vichy.
His widow was the first receiver of the Order of the Francisque.