The No-Conscription Fellowship was a British pacifist organization which was founded in London by Fenner Brockway and Clifford Allen on 27 November 1914, after the First World War had failed to reach an early conclusion. Other prominent supporters included John Clifford, Bruce Glasier, Bertrand Russell, Robert Smillie and Philip Snowden.
A focus of the campaign was the Military Service Act which introduced conscription in 1916. Branches were established across the country, leaflets were produced and deputations sent to lobby Parliament. They were successful in getting provision for conscientious objectors in the bill, but opposed the establishment of the army's Non-Combatant Corps.
The founders and other members were jailed for their opposition to conscription. Bertrand Russell took over from Clifford Allen as the chairman of the organisation while Catherine Marshall took over from Fenner Brockway as secretary. Catherine Marshall was in love with Clifford Allen and, when he was suffering from the effects of imprisonment, she drove herself to the point of exhaustion and Lilla Brockway then took over as secretary in 1917. The National Committee in 1916 was A. Barratt Brown, Alfred Salter, Aylmer Rose, Bertrand Russell, C.H. Norman, Catherine Marshall, Clifford Allen, Edward Grubb, Fenner Brockway, John P. Fletcher, Morgan Jones, Rev. Leyton Richards, Will Chamberlain.