Inez McCormack counted US Secretary of State Hillary Clinton among her friends and was played by Academy Award winning actress Meryl Streep in a play about her life.
Active in the civil rights movement in Northern Ireland in the 1960s, she rose to become the first female president of the Irish Congress of Trade Unions (ICTU).
Current president Eugene McGlone said her track record in women’s and human rights was “unequalled”.
“Her work in promoting the cause of labour and social justice in Northern Ireland was known world-wide,” he said. “Inez’s commitment to social justice began in the ‘60s when she became active in the Northern Ireland civil rights movement.
“She followed this on when she became a trade union and equality activist before becoming the full-time official of the National Union of Public Employees. She also held the post when NUPE was reconstituted in a merger as Unison. Her unstinting passion was recognised and she received many justifiable accolades.”
Patricia McKeown, regional secretary of Unison, said: “The sad day thousands of workers and trade union members have been dreading has come and Inez McCormack, has left us - but only in the flesh. Inez will never leave us in spirit.
“She has touched the lives of thousands of ordinary women and men and she has succeeded in what she set out to do. She has made a difference.”
The Irish president Michael D Higgins said Mrs McCormack was a passionate and committed human rights activist who fought all her life and in so many settings for the creation of a fairer society for workers, for minorities, and for women.
He added: “Inez will be remembered as a great pioneer, who broke through so many challenges and barriers, a brave fighter, and a person of extraordinary generosity whose contribution to an inclusive citizenship and a better world has been immense.”
Sinn Fein president Gerry Adams said she was a fearless opponent of injustice and a determined champion of civil rights, equality, women’s and workers rights, and fair employment.
He said: “For decades Inez was a tireless and effective advocate from her days in the civil rights movement in the 1960s and through her years as a trade union leader... She was a passionate and articulate campaigner who helped place equality at the heart of the Good Friday Agreement. Inez devoted her life to fighting for the oppressed and disadvantaged.”
The Republic’s Foreign Minister Eamon Gilmore said Mrs McCormack played an enormous role in public life on this island, as
President of the Irish Congress of Trade Unions, as a human rights activist and behind-the-scenes in the negotiations of the Good Friday Agreement.
He added: “A brilliant trade unionist, she was an inspiration to countless people in community and public life as she tirelessly challenged the status quo and demanded a better way for working people and working class communities in Ireland, North and South.
Her leadership, at a vital time, undoubtedly helped drive the demand for peace and reconciliation in Ireland.”
The hallmark of her leadership, he said, was insight and analysis backed by action for change.
Meanwhile, US Secretary of State Hillary Clinton, a personal friend, said Mrs McCormack promoted peace and reconciliation for decades in Northern Ireland and around the world.
“She challenged women and men to find a way to put aside their differences, move past hurt and anger and work together to end violence and build a fair and lasting peace. It was a tremendous challenge, but she met it with joy,” she said.
Mrs Clinton added: “Inez used to say that true leadership isn’t a final destination. It’s a process. And it starts with the simple act of stepping up when the opportunity arises.
“From her early days as a community organiser and trade union leader, she stepped up again and again - always with her trademark smile.
“When sectarian conflict was tearing Northern Ireland apart, she brought a diverse group together to find a way toward peace. She also understood that it wasn’t just about stopping the killing; it was about supporting the living.
“So once the Good Friday Agreement was signed, she stayed to help mend communities.
“People called her a hero. She’d say: ‘I’m just a crazy woman who thinks Catholics are the same as Protestants’. Until her final days, she never stopped promoting peace, human rights and equality.
“She travelled the world encouraging young women to be agents of change in their communities and countries.”
Liam Gallagher, chairman of the Irish Executive of Unite and Secretary of Derry Trades Union Council, added: “Inez will be particularly remembered locally for her work in highlighting the plight of low paid workers in the public sector and her tireless campaigns for women’s rights and equality...
“Her colleagues in Unison and the rest of the Trade Union fraternity will miss her fighting spirit and wise counsel.”