Power, Ann (‘Nancy’) Wyse (1889–1963), Celticist, member of Cumann na nBan, and civil servant, was born 16 November 1889 in Dublin, one of the children of John Wyse Power (qv), civil servant, journalist, and founding member of the GAA, and Jennie Wyse Power (qv) (née O'Toole). Members of her family were active in Sinn Féin from the early part of the twentieth century. She became a member of the Gaelic League in 1901 and was a member of the Sinn Féin women's committee campaigning against ‘loyal addresses’ for George V. Her family restaurant business at 21 Henry St. was frequented regularly by leading nationalist figures, including Arthur Griffith (qv), John MacBride (qv), and Henry Dixon. Educated at UCD, where she graduated with a first-class honours BA in Celtic studies (1912), she subsequently began to study for a Ph.D. at the University of Bonn, Germany. Her studies were interrupted by the outbreak of the Great War and she returned to Ireland in 1915. In 1920 she completed her doctorate in Bonn under the professor of Celtic, Julius Pokorny (qv), on the subject of Celtic philology.
Nancy Wyse Power joined Cumann na nBan in 1915, and through her brother Diarmuid she was made aware that a rising was to occur in April 1916. She was asked by Bulmer Hobson (qv) to act as a courier and take a message to Terence MacSwiney (qv) in Cork. On Easter Monday she was sent to Carlow to convey messages to the Volunteers, returning on Easter Tuesday to Dublin, where she joined the garrison in the GPO, assisting in the carrying of messages and moving of provisions. Throughout 1916–17 she was active in providing relief for the families affected by the rising. Appointed one of two honorary secretaries of Cumann na nBan in autumn 1917, she was active in the reorganisation and restructuring of that organisation, which by 1920 numbered over 500 branches throughout the country. In 1917 she was nominated by Constance Markievicz (qv) to take her place on the Sinn Féin executive if the leadership were arrested, as happened after the ‘German plot’ of 1918. In July 1918 Cumann na nBan was proscribed but not suppressed. Later that year Nancy Wyse Power was responsible for supplying Sinn Féin meetings with speakers. She remained an active member of Cumann na nBan during the war of independence.
She was recruited to Dáil Éireann's fledgling foreign service, becoming a member of its short-lived committee for foreign affairs, which had a budget of £1,000. In April 1921 she travelled to Berlin, where she set up the offices of the Irish political mission, of which John Chartres (qv) later took over the leadership. They succeeded in resurrecting the news-sheet, the Irish Bulletin. An Irish trade mission also operated in Berlin, under the direction of Charles Bewley (qv), who in 1922 succeeded in having the political mission closed, getting both Power and Chartres recalled for alleged anti-treaty sympathies. In fact Power was not anti-treaty, and on her return to Ireland she joined the Department of Industry and Commerce in 1923. In 1929 she and her mother, Senator Jennie Wyse Power, moved to 15 Earlsfort Terrace, Dublin. In 1932, at the request of Sean T. O'Kelly (qv), Nancy Wyse Power was transferred from Industry and Commerce and was appointed his personal private secretary in the Department of Local Government and Public Health. She was one of the first women to rise to the position of principal officer in the Irish Free State civil service, where she was an advocate of equality for women in the service. She retired from the Department of Local Government as principal officer in 1954.
Nancy Wyse Power was appointed one of the governors of the Dublin Institute for Advanced Studies from 1940 until her death. She was president of the UCD Women Graduates Association 1959–62. She never married and died 27 December 1963 in Dublin. Her brother Charles Stewart became a circuit court judge, and her sister Maura Wyse Power (qv) was a Gaelic scholar.