The Great War altered the means by which women conducted political activity as they adapted to wartime circumstances, while also bringing new opportunities for women’s mobilisation and politicisation. Competing loyalties of suffrage, nationalism, republicanism and unionism also affected attitudes towards Irish women’s role in the war effort and provided dissenting voices against the mechanisms of wartime mobilisation. This chapter examines the mobilisation of suffragist, nationalist and unionist women for the war effort, the participation of women in acts of dissent and the impact of the war on the achievement of female suffrage in 1918. It contrasts the opportunities for politicisation offered by the nationalist and unionist movements and argues that the differing approaches to the war effort resulted in the further polarisation of unionist Ulster and southern Ireland. The chapter argues that the war created a space for political activism, evident through the mass mobilisation of previously unorganised women in the 1918 anti-conscription campaign and the actions of working-class soldiers’ wives in Ireland in defending their interests against the growing republican movement.