Mary Josephine Ryan was an Irish Nationalist. A member of Cumann na mBan and the honorary secretary of the executive committee, she took part in the 1916 Easter Rising and the War of Independence.

Cumann na mBan, abbreviated C na mB, 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 Irish Volunteers, and later, the Irish Republican Army.