Born into a patrician family, he graduated from the prestigious military schools at Saint-Cyr (1924) and Saumur. In 1939, as a captain of infantry, he was wounded and captured by the Germans, but he managed to escape to England. Upon hearing that General Charles de Gaulle (Gaulle, Charles de) was rallying Free French Forces from London, he took the name Leclerc (so as to spare his family in France any reprisals) and joined de Gaulle. Promoted to colonel by de Gaulle, he achieved a number of military victories in French Equatorial Africa. After being promoted to brigadier general, he staged a spectacular 1,000-mile (1,600-km) march from Chad to Tripoli, Libya, to join the forces of the British Eighth Army, capturing Italian garrisons along the way. He was promoted to major general in 1943.

He took part in the Normandy Invasion of 1944 as commander of the Free French 2nd Armoured Division, which debarked on August 1 and took part in the drive to Alençon and Argentan by U.S. General George S. Patton (Patton, George Smith)'s Third Army. On August 20 the 2nd Armoured Division was ordered by Supreme Allied Commander Dwight D. Eisenhower (Eisenhower, Dwight D.) to liberate the French capital, and on August 25 the commander of the German garrison in Paris, Dietrich von Choltitz (Choltitz, Dietrich von), surrendered to Leclerc. The next day Leclerc and de Gaulle formally entered Paris in triumph.

Leclerc went on to liberate Strasbourg (November 23, 1944) and then led his men on into Germany, capturing Berchtesgaden. In July 1945 Leclerc was named commander of the French expeditionary force to the Far East. That same year he legally changed his name from Philippe-Marie, vicomte de Hauteclocque, to Jacques-Philippe Leclerc de Hauteclocque, using his wartime name.

In March 1946 Leclerc was sent to French-occupied Indochina. He perceived that the nature of the problems there was more political than military, but he aroused controversy with that message in France and resigned his post. In July 1946 he became inspector general of the French forces stationed in North Africa. He was killed there in an airplane accident. In 1952 the French government posthumously named him marshal of France.