Cumann na mBan, abbreviated CnamB, is an Irish republican women's paramilitary organisation formed in Dublin on 2 April 1914, merging with and dissolving Inghinidhe na hÉireann, and in 1916 it became an auxiliary of the Irish Volunteers. Although it was otherwise an independent organisation, its executive was subordinate to that of the Volunteers.
In 1913, a number of women decided to hold a meeting in Wynn's Hotel, Dublin, for the purpose of discussing the possibility of forming an organisation for women who would work in conjunction with the recently formed Irish Volunteers. A meeting led by Kathleen Lane-O'Kelly (née Shannahan) on 2 April 1914 marked the foundation of Cumann na mBan. Branches,which pledged to the Constitution of the organisation, were formed throughout the country and were directed by the Provisional Committee. The first branch was named the Ard Chraobh, which held their meetings in Brunswick Street, before and after the 1916 Easter Rising.