The so-called Guildford Four served 15 years of life sentences after being wrongly convicted for the 1974 IRA bombing of a pub in the Surrey town before the verdicts were overturned in 1989.
Conlon had suffered two breakdowns, attempted suicide and became addicted to drugs and alcohol following his release. He said he had started having nightmares only after securing freedom: “The ordeal has never left me.”
Conlon said on gaining his freedom: “I have been in prison for something I did not do. I am totally innocent.”
Sir Daniel Day-Lewis was nominated for an Oscar for playing Conlon in the 1993 film In The Name Of The Father.
The bomb attack on the Horse and Groom pub killed five people, including four soldiers, and injured 65.
The others wrongly convicted were Paddy Armstrong, Paul Hill and Carole Richardson. The Court of Appeal quashed their sentences amid doubts raised about the police evidence against them.
An investigation by Avon and Somerset Police found serious flaws in the way Surrey Police handled the case.
Four years ago, Prime Minister Tony Blair became the first senior politician to apologise to the Guildford Four.
Conlon died in his home in the Falls Road area of Belfast.
A family statement said: “He brought life, love, intelligence, wit and strength to our family through its darkest hours. He helped us to survive what we were not meant to survive.
“We recognise that what he achieved by fighting for justice for us had a far, far greater importance – it forced the world’s closed eyes to be opened to injustice; it forced unimaginable wickedness to be acknowledged; we believe it changed the course of history.
“We thank him for his life and we thank all his many friends for their love.”
Conlon’s father Giuseppe, who was jailed as part of a discredited investigation into a supposed bomb-making family – the Maguire Seven – died in 1980 after four years in jail. His mother Sarah, a tireless campaigner for their freedom, died in 2008, aged 82.
Yesterday Sinn Fein president Gerry Adams said: “Gerry and his father Giuseppe were two of the most infamous examples of miscarriages of justice by the British political and judicial system.
“To his family and friends I want to extend my sincere condolences.”
Alex Attwood, the SDLP Stormont Assembly member for the Falls Road area, said: “He’d given an awful lot but yet had so much more to give.
“What he learned from his time in prison and campaign for release was the importance of not only raging against his own injustice but fighting for those who had also suffered miscarriages of justice.”
Conlon in recent years took up the cause of a number of dissident republicans jailed in Northern Ireland, including Marian Price. She was convicted of offences linked to paramilitaries including providing a phone used by the Real IRA hit squad that murdered two British soldiers at the Massereene barracks in County Antrim in 2009.
He insisted his approach was not political but for the right of people to have a fair trial and the right for justice to be seen to be done in public.