Tributes poured in for Hume from across the political spectrum.
"John Hume was a political titan; a visionary who refused to believe the future had to be the same as the past," said former British prime minister Tony Blair, who helped craft the Good Friday Agreement.
"His contribution to peace in Northern Ireland was epic and he will rightly be remembered for it."
Irish Prime Minister Micheal Martin said it was "impossible to properly express the scale and significance of John Hume's life".
"He was one of the towering figures of Irish public life of the last century. His vision and tenacity saved this country," he said.
Northern Ireland's First Minister Arlene Foster, leader of the pro-British Democratic Unionist Party, called Hume "a giant in Irish nationalism".
"In our darkest days he recognised that violence was the wrong path (and) worked steadfastly to promote democratic politics," she added.
Hume's own party, the SDLP, said: "We all live in the Ireland he imagined - at peace and free to decide our own destiny."
'Living for ideals'
Born in the Northern Irish city and republican stronghold of Londonderry in 1937, Hume joined the province's civil rights movement in the late 1960s as Catholics demanded equality in housing, voting and other issues.
He was elected to Northern Ireland's parliament as an independent lawmaker, becoming a founding member of the SDLP in 1970, before later serving as a member of the European Parliament and then Britain's House of Commons.
As the province's peace process began to progress in the 1990s with several ceasefires by the Irish Republic Army (IRA) paramilitary group, Hume worked to engage US politicians, notably Bill Clinton.
"The answer to difference is to respect it," Hume summarised in his Nobel acceptance speech in December 1998.
"I want to see Ireland as an example to men and women everywhere of what can be achieved by living for ideals, rather than fighting for them, and by viewing each and every person as worthy of respect and honour."
Hume resigned as leader of the SDLP in 2001, citing ill health.
Hume's family said his funeral would be arranged in accordance with current government regulations severely limiting the number of attendees due to the risk of spreading coronavirus.
"We realise this will mean that many will be unable to join us, and we will arrange a memorial service and a celebration of his life in due course," they said.