The Quit India Movement was a movement launched at the Bombay session of the All India Congress Committee by Mahatma Gandhi on 8 August 1942, during World War II, demanding an end to British rule in India. After Britain failed to secure Indian support for the British war effort with the Cripps Mission, Gandhi made a call to Do or Die in his Quit India speech delivered in Bombay on 8 August 1942 at the Gowalia Tank Maidan. Viceroy Linlithgow described the movement as "by far the most serious rebellion since 1857".

The All India Congress Committee launched a mass protest demanding what Gandhi called "An Orderly British Withdrawal" from India. Even though it was at war, Britain was prepared to act. Almost the entire leadership of the Indian National Congress was imprisoned without trial within hours of Gandhi's speech. Most spent the rest of the war in prison and out of contact with the masses. The British had the support of the Viceroy's Council, of the All India Muslim League, the Hindu Mahasabha, the princely states, the Indian Imperial Police, the British Indian Army, and the Indian Civil Service. Many Indian businessmen profiting from heavy wartime spending did not support the Quit India Movement. The major outside support came from the Americans, as President Franklin D. Roosevelt pressured Prime Minister Winston Churchill to give in to some of the Indian demands.

The movement included anti-British boycotts and rejection of transactions involving the colonial government. Various violent incidents took place around the country against British rule, and the colonial government arrested tens of thousands of leaders, keeping them imprisoned until 1945. Ultimately, the British realised that India was ungovernable in the long run, and the issue for the postwar era became how to exit gracefully and peacefully. The movement ended in 1945 with the release of all jailed nationalists. Prominent independence activists who died during the movement included Mukunda Kakati, Matangini Hazra, Kanaklata Barua, Kushal Konwar, Bhogeswari Phukanani and others. In 1992, the Reserve Bank of India issued a 1 rupee commemorative coin to mark the Golden Jubilee of the Quit India Movement.

In 1939, Indian nationalists were angry that British Governor-General of India, Lord Linlithgow, brought India into the war without consultation with them. The Muslim League supported the war, but Congress was divided.

At the outbreak of war, the Congress Party had passed a resolution during the Wardha meeting of the working committee in September 1939, conditionally supporting the fight against the Axis, but were rebuffed when they asked for independence in return:

If the war is to defend the status quo of imperialist possessions and colonies, of vested interest and privilege, then India can have nothing to do with it. If, however, the issue is democracy and world order based on democracy, then India is intensely interested in it... If Great Britain fights for the maintenance and expansion of democracy, then she must necessarily end imperialism in her possessions and establish full democracy in India, and the Indian people have the right to self-determination... A free democratic India will gladly associate herself with other free nations for mutual defence against aggression and for economic co-operation.

Gandhi had not supported this initiative, as he could not reconcile an endorsement for war (he was a committed believer in non-violent resistance, used in the Indian Independence Movement and proposed even against Adolf Hitler, Benito Mussolini, and Hideki Tojo). However, at the height of the Battle of Britain, Gandhi had stated his support for the fight against racism and of the British war effort, stating he did not seek to raise an independent India from the ashes of Britain. However, opinions remained divided. The long-term British policy of limiting investment in India and using the country as a market and source of revenue had left the Indian Army relatively weak and poorly armed and trained and forced the British to become net contributors to India's budget, while taxes were sharply increased and the general level of prices doubled: although many Indian businesses benefited from increased war production, in general business "felt rebuffed by the government" and in particular the refusal of the British Raj to give Indians a greater role in organising and mobilising the economy for wartime production.

Subash Chandra Bose remarked that a "new chapter in Indian freedom struggle began with the Quit India Movement". After the onset of the world war, Bose had organised the Indian Legion in Germany, reorganised the Indian National Army with Japanese assistance and, soliciting help from the Axis Powers, conducted a guerrilla war against the British authorities.