The Roscommon-born politician and businessman passed away shortly before 3am, according to his family.
He is survived by his wife Kathleen, two sons and five daughters.
Living in Longford for most of his life he was considered an astute deal-maker - credited with securing billions in funding from the EU to kick-start a faltering Irish economy.
But it's for his negotiating talents in driving forward the peace process in Northern Ireland that he will be most remembered, working with British prime minister John Major to secure an IRA ceasefire that was to start the delicate and sensitive talks that would eventually lead to a lasting peace.
Tributes to the man who led Fianna Fail through turbulent times were paid today by many he shared political life with, both as allies and opponents.
President Michael D Higgins said it was with great sadness he learned of the death of Mr Reynolds. "I wish to express my deepest sympathy to Kathleen and the entire Reynolds family," he said.
"Albert Reynolds will be remembered as a most dynamic Cabinet Minister and a Taoiseach with courage, who made a very important contribution to the dialogue which led to the Northern Ireland peace process. When I served in cabinet with him, I found him to be very supportive of many of the cultural initiatives which I introduced. I recall his great courtesy and relaxed manner in all our dealings on various issues."
Taoiseach Enda Kenny is offering the Reynolds family a State funeral, as is the norm when former Taoisigh die.
Officials from the Taoiseach's office will meet with members of the family later today to discuss the funeral arrangements.
"Albert Reynolds brought an energy and drive to the development of business and economic growth during his tenure in office as Minister for Industry and as Minister for Finance," Mr Kenny said.
"As Taoiseach he played an important part in bringing together differing strands of political opinion in Northern Ireland and as a consequence made an important contribution to the development of the peace process which eventually lead to the Good Friday Agreement," he added.
British prime minister David Cameron tweeted: "Sad to hear of death of Albert Reynolds. Partnership with Sir John Major led to '93 Downing St declaration: landmark in NI peace process."
Sinn Fein president Gerry Adams paid tribute to Albert Reynolds' approach to securing Northern peace.
"Albert's biggest achievement was the part he played in the peace process," he said. "He did the right thing by the north when it mattered."
"A lot of work had been done behind the scenes but no one had seized the moment in the very down-to-earth straight forward way that he did," he explained.
Mr Reynolds' successor, Bertie Ahern, praised Albert as a family man and politician.
"The Downing Street declaration in December 1993 was really the foreword to the whole ceasefire and the work afterwards that I continued on in," he said.
"If there hadn't have been a Downing Street declaration I don't think there would've been a ceasefire in the first place," Mr Ahern added.
Bertie Ahern said that apart from his work in the North, Albert Reynolds also had an objective to revitalise the economy.
"Being a good businessman, and a good tactician, he worked hard within the European system to get resources, which is what gave the great kick-off right through the 90s to the Irish economy," he said.
Former Taoiseach and Fine Gael leader John Bruton praised Albert, although they worked on different sides of the political divide.
"We were political rivals but he was always a kind man. I know how devoted he was to Kathleen and the family," he said.
Mr Bruton said the Downing Street declaration was an enduring legacy of Albert Reynolds.
"The negotiation of the Downing Street declaration was absolutely crucial," he said today. What we were trying to do on one hand was to persuade SF and the IRA that the use of violence was not going to achieve anything," he added.
Addressing the short tenure of Reynolds as Taoiseach, Mr Bruton said: "It's not the length of time you serve, it's the strength of the contribution he made."
Current Fianna Fail leader Micheal Martin also paid tribute to Reynolds and his "ability to develop trust and build relationships".
Mr Martin remembered Mr Reynolds as "a person that you could talk very readily with".