The No More War Movement was the name of two pacifist organisations, one in the United Kingdom and one in New Zealand.
The British No More War Movement (NMWM) was founded in 1921 as a pacifist and socialist successor to the No-Conscription Fellowship. For the first two years of its existence, it was known as the No More War International Movement. It became the British section of War Resisters International. Chaired by Fenner Brockway, it asked members to strive for revolutionary socialism but not to take part in any war. Other notable NMWM members included Wilfred Wellock,Leslie Paul, A. Barratt Brown, Leyton Richards, W. J. Chamberlain and Monica Whately. The movement also received messages of support from several international figures, including Albert Einstein. In 1926, a member proposed the creation of a white poppy, in the manner of the British Legion's red poppies, but with the added meaning of a hope for an end to all wars. The group did not pursue the idea, but it was later taken up by the Women's Co-operative Guild. At its peak, the NMWM numbered around 3000 members, many from the Independent Labour Party. In 1929, several prominent British intellectuals signed a statement, "Why I Believe in the No More War Movement", supporting the NMWM's aims. The group published two journals: The New World and No More War.
After Brockway resigned in 1929, and secretaries Walter Ayles and Lucy Cox left in 1932, the group foundered. Reginald Reynolds, a Quaker influenced by Gandhi, became general secretary, but he could not stop a drift of members to the communist British Anti-War Movement and the New Commonwealth Society. Anarchists became increasingly prominent, but most left after the Movement, in accordance with its pacifist principles, refused to support the fighting of either side in the Spanish Civil War. In 1937 the organisation formally merged with the Peace Pledge Union, although the Midlands Council of the NMWM retained an independent existence for a year or so.