O'Leary, Ellen (1831–89), nationalist and poet, was born 22 October 1831 in Tipperary town, the second child of John O'Leary, a prosperous shopkeeper, and his second wife Margaret Ryan. After the death of her mother in the mid 1830s while she was still a very young child, Ellen and her brothers John (qv), the future Fenian leader, and Arthur (1833–61) were reared by an aunt. Her father eventually remarried and had two more children with his third wife.
Ellen spent most of her adult life in a cottage in Tipperary town, where she lived independently, having inherited a modest income on her father's death. This quiet existence was interrupted by periods spent with her brothers in their student lodgings in Dublin and London. Intelligent, sensitive and bookish, she spent much of her time working with local catholic charities and, from her early twenties, producing poetry, which often reflected her commitment to the nationalist cause. In time she became a contributor to a variety of journals, among them the Nation, Commercial Journal, Irishman, Shamrock, Irish Fireside, the Irish-American Boston Pilot, and in later years the Irish Monthly. She also went on to become closely associated with the Fenian journal the Irish People (1863–5), co-edited by her brother John, her poetic contributions appearing under the pseudonyms ‘Eily’ and ‘Lenel’. Throughout these years she became increasingly active in nationalist politics and regularly came to Dublin to attend Fenian meetings at her brother's lodgings. After the arrests of prominent Fenians, including her brother John, in September 1865, she was employed by the IRB leader James Stephens (qv) to carry messages in Dublin and also to Paris. When Stephens escaped from Richmond prison (24 November 1865), she facilitated his flight by mortgaging her property for £200 to charter a ship to take him to France. After Stephens's flight Edward Duffy (qv) assumed effective leadership of the IRB and Ellen began working for him. They fell in love and became engaged, much to the displeasure of John O'Leary who had a poor opinion of Duffy. Duffy, however, was arrested (9 March 1867) and sent to Millbank prison, where he died 17 January 1868. His death strongly affected the highly sensitive Ellen, reinforcing her quiet, retiring, and melancholy manner.
She moved back to Tipperary but travelled regularly to visit her brother in prison in England and in Paris after his release in 1871. In the 1880s she renewed her political activities, attending the inaugural meeting of the Ladies's Land League in January 1881, at which she was elected treasurer. After John's return to Ireland in 1885 she left Tipperary and set up house with him in Dublin. Their home at 40 Leinster Road, Rathmines, became a meeting place for leading Irish writers, nationalists and intellectuals, notably W. B. Yeats (qv), whose poetry appeared alongside Ellen's in the Celtic revival's seminal publication Poems and ballads of Young Ireland (1888). Her own ‘at homes’ were attended by many well known women poets, among them Katharine Tynan (qv), Rosa Mulholland (qv), Rose Kavanagh (qv), and Dora Sigerson Shorter (qv). With her brother she joined the Pan-Celtic Society (founded in 1888), and contributed to its Lays and lyrics of the Pan-Celtic Society (1889). She also contributed to the GAA's short-lived journal The Gael (1887–8), co-edited by John O'Leary. These years of activity and recognition were happy in many ways, but were marred by poor health. She was diagnosed with breast cancer in 1885, after which she underwent an operation which failed to arrest its growth. She died 16 October 1889 in the home of her nephew John King in Castle Street, Cork, and was buried in the O'Leary family plot in Tipperary. John O'Leary was particularly distraught at her death, recalling that ‘She was everything to me, as I was everything to her’ (O'Leary, ii, 97). A collection of her verse, which Maud Gonne (qv) and C. H. Oldham (qv) had helped prepare before her death, was published with an introduction by Sir Charles Gavan Duffy (qv) in 1891, and established her reputation as a leading Fenian poet.