Gaston-Henri Billotte (10 February 1875 – 23 May 1940) was a French military officer, remembered chiefly for his central role in the failure of the French Army to defeat the German invasion of France in May 1940. He was killed in a car accident at the height of the battle.
Billotte was born at Sommeval, in the Aube. He graduated from the Saint-Cyr military academy in 1896 and joined the infantry.
In World War I he served as a brigade commander and as an officer of the General Staff.
In 1919-20 he was head of the French Military Mission in Poland. He served the rest of the 1920s and 1930s in colonial posts, in Syria, Tunisia, Morocco and French Indochina, where he was Commander-in-Chief from 1930 to 1932. He was promoted to general in 1927. In 1933 Billotte returned to France, where he served as a Member of the Supreme War Council, President of the Consultative Committee for Colonial Defence and Military Governor of Paris.
When World War II broke out in September 1939 Billotte was 64 and close to retirement, but he was appointed Commander in Chief of the 1st Army Group based in northern France adjacent to the Belgian border. When the Germans attacked on 10 May, Billotte's forces advanced into Belgium under the agreed Allied plan, on the assumption that the Germans would repeat their manoeuvre of World War I, attacking through Belgium into northern France, and then advance on Paris. According to the Manstein Plan, the German attack in Belgium was a feint designed to draw the Allied forces northwards, while the real German assault was aimed at the Ardennes sector further south. Like all the Allied commanders, Billotte failed to discern the German plan.
On 12 May Billotte was given the task of co-ordinating the operations of the French, Belgian and British armies in Belgium. He lacked the staff and the experience for this task, and is reported to have burst into tears when informed of it. He failed to co-operate with the British commander, General Lord Gort, and the Belgian commander, King Leopold. By 15 May Billotte's morale was "at rock bottom." After a meeting with Gort on 18 May, he remarked to a British officer: "I'm shattered and I can't do anything against these Panzers."