Chief executive of the Swiss Ski Federation Bernhard Aregger said the organisation was "deeply saddened" to learn of Kasper's death.
"For 46 years he shaped snow sports in a leading position at FIS - 23 years as general secretary and another 23 years as President," said Aregger.
"We mourn the loss of a great snow sports personality and we will always keep an honourable memory of Gian-Franco Kasper."
Kasper was also an honorary member of the International Olympic Committee (IOC), a former President of the Association of International Olympic Winter Sports Federations, a member of the Global Association of International Sports Federations and a member of the SportAccord Council.
He also served as vice-president of the IOC Olympic Channel Services and the IOC Coordination Commissions for six Winter Olympic Games.
He was also involved with the IOC Coordination Commission for two Winter Youth Olympic Games, chairing the Commission for Innsbruck 2012 and acting as a member for Lillehammer 2016.
He had been due to stand down as FIS President in June 2020 but stayed on for an additional year after the coronavirus pandemic forced the Congress to be postponed twice.