Appointed honorary life president of the International Olympic Committee (IOC) when he stepped down as president in 2001, Samaranch was admitted to the Quiron clinic in his native Barcelona on Sunday with acute heart problems and passed away at 1325 local time (4.55 pm IST) on Wednesday.
He had died as a result of "cardio-respiratory failure" hospital doctor Rafael Esteban said in a statement.
"I cannot find the words to express the distress of the Olympic Family," IOC president Jacques Rogge said. "We have lost a great man, a mentor and a friend who dedicated his long and fulfilled life to the Olympics."
Once one of the most powerful figures in world sport, who wielded influence on the Olympic movement right up until his death, Samaranch had suffered a number of health problems since his retirement and was admitted to hospital several times.
He ran the IOC with absolute authority for two decades and the 1992 Olympics in Barcelona, which transformed the Catalan port city, were seen as his personal triumph.
His supporters believe he showed political skill in a difficult period -- a US-led boycott of the 1980 Moscow Olympics followed by an eastern-bloc retaliation in 1984 at Los Angeles -- to lead the Games into the era of professional sport and turn it into a huge money-spinner.
His critics argue that many of the original values of the movement were obscured in the search for commercial success, leading to high-profile bribery and drugs scandals.
He stepped down in July 2001, 21 years after he had been elected as the IOC's seventh president, and was made life president when he handed power to Rogge.
At last October's vote in Copenhagen on the host for the 2016 Games, Samaranch made an emotional appeal to IOC members to grant him a last favour and choose Madrid but they picked Rio de Janeiro instead. "I know that I am very near the end of my time," Samaranch said during Madrid's final presentation.
Born on July 17 1920, Samaranch enjoyed success as a roller skater and led the Spanish team to the world title. He pursued a career in sports politics in dictator Francisco Franco's fascist Spain and won a place on the IOC in 1966.
After Franco's death, he was appointed ambassador to the Soviet Union and the contacts he made there helped him succeed Lord Killanin as IOC president in 1980.
Almost immediately Samaranch was confronted with a crisis which threatened the future of the Games with a US-led western boycott of the Moscow Olympics followed by an eastern bloc retaliation in 1984 at Los Angeles.
Spectacular show
Los Angeles not only provided a spectacular show, it was also a financial success and represented a clear break with the past with its focal sport of athletics now fully professional. The 1992 Barcelona Games, held in Samaranch's birthplace, were a stunning success as corporate sponsors queued to join the party and the price of television rights soared.
Boycotts were over and all seemed well in the Olympic movement, but there were mutterings of bribes to IOC members in the now fiercely competitive bids to host the winter and summer Games. Allegations of drugs cover-ups also persisted.
A series of high-profile drug busts including the Festina scandal at the 1998 Tour de France prompted the International Olympic Committee to call a special anti-doping conference at its Lausanne headquarters in early 1999 and to establish the World Anti-doping Agency (WADA).
Another scandal struck when veteran IOC member Marc Hodler, who had run against Samaranch for the presidency, told reporters some members had been bribed to award the 2002 Winter Games to Salt Lake City. The allegations were confirmed and, to their horror, IOC members found themselves international pariahs enduring stinging attacks from politicians and the world's media.
Samaranch faced calls to quit from the media at the height of the Salt Lake scandal. But Samaranch still won a vote of confidence from IOC members with ease.
The final decisions made during Samaranch's tenure were the decision to award Beijing the right to stage the 2008 Olympics despite widespread criticism of China's human rights record and the election of his chosen successor Rogge as the new IOC president.
Samaranch's supporters believe he saved the Olympic Games from destruction and demonstrated subtle political skills in a difficult time. His critics argue that many of the original ideals were obscured in the search for commercial success. 
