Catherine Ita Ahern (née Liston; 13 January 1915 – 27 December 2007) was an Irish Fianna Fáil politician who served as a Teachta Dála (TD) for the Kerry North constituency from 1977 to 1981 and a Senator from 1964 to 1977. Ahern was the first woman to hold several political offices, such as first woman to chair Kerry County Council. At the 1977 general election she was one of only three women elected to the 21st Dáil.

A member of Fianna Fáil, during the 1970s and 1980s Ahern exemplified the convergence of Irish nationalism and social conservatism that was growing in the party at the time, supporting the functional use of the Irish language while opposing contraception, divorce, annulment and women with children working outside the home. In the 1979 Fianna Fáil leadership election, she supported the failed attempt by George Colley and thereafter fell afoul of his successful rival Charles Haughey, who prevented her from returning to the Seanad by favouring others. Starved of political support within Haughey's Fianna Fáil, she retired from national politics by the mid-1980s. Her Parthian shot was to defect to the newly created Progressive Democrats in 1985, a splinter party from Fianna Fáil filled with many of Haughey's opponents.

She was born in Athea, County Limerick, the eldest of eight children. She grew up in a politically conscientious household: Her father, Patrick Liston, was known as "the Painter" because he painted banners for Parnellite rallies while her grandmother Kate McAuliffe had been involved in the Ladies' Land League. During the Irish Civil War the Listons supported the Anti-Treaty IRA and from then onwards were considered staunch Irish Republicans. Ahern's uncle Owen McAuliffe was a member of the Limerick IRA and was imprisoned for his activities.

Ahern's first political activity was in about 1934 when she and another classmate walked out of the classroom at her school to protest against other classmates wearing blue shirts in support of the Army Comrades Association.

Ahern was educated locally and at the College of Art in Dublin, and went on to work as a teacher at Coláiste Mhuire in Abbeyfeale, County Limerick. Ahern became involved with the Irish Countrywomen's Association (ICA), becoming the organisation's president in 1961, and she also served on the board of Bord Fáilte.

Ahern's first major political role came in 1964, when she was nominated to Seanad Éireann by the Taoiseach, Seán Lemass, to fill a vacancy caused by the death of Pádraig Ó Siochfhradha.

Ahern contested the Dáil elections of 1965, 1969 and 1973, but was unsuccessful on all three occasions. However, she retained her Seanad seat, initially as a Taoiseach's nominee, and in 1969 and 1973 she was elected as a Senator for the Cultural and Educational Panel. After her re-election in 1973, she was nominated by Fianna Fáil Senator Brian Lenihan for the post of Leas-Chathaoirleach of the 13th Seanad. The post had traditionally been held by a member of an opposition party, but the incoming National Coalition government of Fine Gael and the Labour Party decided that it wanted a Labour Party deputy to a Fine Gael Cathaoirleach James Dooge. Labour's Evelyn Owens was elected as Leas-Chathaoirleach, but Ahern won the support not just of her Fianna Fáil colleagues but also of Mary Robinson then an independent senator.

Ahern became a member of Kerry County Council in 1967, and from 1977 to 1978 she was the council's first woman Cathaoirleach (chairperson).