Miriam Daly (née McDonnell; 6 May 1928 – 26 June 1980) was an Irish republican and communist activist as well as a university lecturer who was assassinated by the loyalist Ulster Defence Association (UDA) in 1980.

She was born Miriam Annette McDonnell in the Curragh Irish Army camp, County Kildare, Ireland, one of the two daughters of Commandant Daniel McDonnell and Anne McDonnell (née Cummins). Her father had served under Michael Collins in the War of Independence and as part of the pro-treaty National Army during the Irish Civil War. Afterwards, he developed pro-Labour views.

She grew up in Hatch Street, Dublin, where she attended Loreto College on St Stephen's Green and then University College, Dublin. While at UCD, Daly was a member of Young Fine Gael. She graduated with a Bachelor of Arts degree in 1948 with first-class honours in history and economics, a Higher Diploma in Education in 1949, and then a first-class honours Master of Arts, with a dissertation on Irish labour in England in the first half of the nineteenth century. Between 1950 and 1953 she taught economic history as an assistant lecturer in University College Dublin alongside Robert Dudley Edwards, who sexually harassed her until one day her father arrived with a gun and confronted Edwards.

In 1953 she married the psychiatrist Joseph Lee and together the two moved to England, where she was an extramural history lecturer. She became an active member of the Association of University Teachers and a campaigner against the Vietnam War. Lee died of a heart attack in 1963. A year later she began teaching economic history at the University of Southampton.

In 1965 she married philosopher and social activist James Daly, who had family from Ulster. They moved to Ireland in 1968 and were appointed lecturers in the departments of scholastic philosophy and of economic and social history at Queen's University, Belfast. In 1970 they adopted twins.

Apart from her set course, Daly taught an extramural course on labour history whose students included numerous Protestant trade unionists. She also lectured both republican and loyalist prisoners in Long Kesh and cooperated with both on prisoner welfare work. She contributed regularly to RTÉ Radio's Thomas Davis lectures in 1972–3. She was a founding member of the Irish Labour History Society, served on its committee for several years and co-edited its journal Saothar. She was a co-founder of the Economic and Social History Society of Ireland, a committee member of the Ulster Society for Irish Historical Studies, a member of the editorial board of Irish Historical Studies, and organised the first conference on Irish labour history held at an Irish university in 1974.

Daly became active in the Northern Ireland civil rights movement following the introduction of internment without trial of suspected IRA members in 1972 by Westminster officials at the request of Prime Minister of Northern Ireland Brian Faulkner. She was active in the Northern Ireland Civil Rights Association (NICRA), and the Northern Resistance Movement (NRA), becoming involved in the former when she moved to Belfast; Daly subsequently joined the National Democratic Party (NDP), and its successor, the Social Democratic and Labour Party (SDLP). As a member of the SDLP she butted heads with John Hume and opposed advocacy for increased private home ownership rather than extended state housing. At the first SDLP annual conference, Daly led opposition to a motion condemning all political violence that was proposed by Hume.

The rapid escalation of violence in Northern Ireland during this period, in particular, the killing of 14 civil rights marchers by members of 1 PARA in Derry on 14 January 1972 in what later became known as "Bloody Sunday" further radicalised her. After Bloody Sunday, she left the SDLP and joined Sinn Féin in 1974.