On August 17, 1943, the First Quebec Conference (codenamed QUADRANT) began in Quebec City. It was a highly secret military conference held during World War II between the British, Canadian and United States governments. The chief representatives of each country were Winston Churchill, Franklin D. Roosevelt and William Lyon Mackenzie King.

At the conference, which began on August 17, 1943 and lasted until August 24, the allied nations discussed plans for several areas of the war. They agreed to begin planning on the invasion of France, an invasion which was codenamed Overlord. There were also discussions about increasing the bombing offensive against Germany and continuing the buildup of American forces in Britain prior to an invasion of France. In the Mediterranean, they decided to concentrate more force on Italy, with the goal of removing it from the alliance of Axis Powers and ultimately occupying it. Operations against Japan would be intensified in order to exhaust Japanese resources, cut their communication lines, and secure bases from which the Japanese mainland could be attacked.

In addition to the strategic discussions, which were later detailed to the allies in the Soviet Union China, the conference also condemned German atrocities in Poland.

A second Quebec Conference, codenamed OCTAGON, was held a year later. These conferences ultimately helped the Allies strategize a way to win the war.