President Samaranch was suffering from severe heart trouble at the age of 89 and was admitted to the Quiron hospital in Barcelona on Tuesday.
Juan Antonio Samaranch was President of the IOC from 1980 to 2001 and was elected Honorary Life President in 2001.
Olympic Council of Ireland President and IOC Member Patrick Hickey will leave today to attend the funeral tomorrow in Barcelona.
Current IOC president Jacques Rogge paid tribute to his predecessor, saying: “I cannot find the words to express the distress of the Olympic Family.
“I am personally deeply saddened by the death of the man who built up the Olympic Games of the modern era, a man who inspired me, and whose knowledge of sport was truly exceptional.
“Thanks to his extraordinary vision and talent, Samaranch was the architect of a strong and unified Olympic Movement. I can only pay tribute to his tremendous achievements and legacy, and praise his genuine devotion to the Olympic Movement and its values. We have lost a great man, a mentor and a friend who dedicated his long and fulfilled life to Olympism.”