This paper will explore inter-war transnational intellectual networks around intellectual co-operation in the International Federation of University Women and the International Council of Women. It will consider meanings attributed to intellectual co-operation by both organisations and ways that both organisations and their members were embedded in complex wider networks (of men and women) that related to the League of Nations Committee of Intellectual Co-operation and to national committees of Intellectual Co-operation. It will look how transnational women’s networks around intellectual co-operation included women with affiliations to middle-class women’s organisations and to socialist organisations, and linked professional women with high academic achievements, members of international teachers organisations, and members of the League Secretariat. It will consider ways in which women’s intellectual networks around intellectual co-operation worked to facilitate pacifism and social reform across Europe and to advance the education of women.