Lim, Malaysia's third-richest individual with a net worth of $4.3 billion (2.1 billion pounds) according to Forbes magazine, died at a medical centre on the outskirts of Kuala Lumpur, said grandson Justin Leong, Genting's head of strategic investments.
"He died peacefully in his sleep," Leong said.
Lim retired as group chairman at end-2003 and took no further part in running the business he set up in 1965. Genting is now run by his son, Lim Kok Thay, who is chairman and CEO.
Shares in Genting, which is building a $3.4 billion casino in Singapore as part of a major overseas expansion, did not move on the news. A broker said most investors were aware that the founder had handed over management to his heirs many years ago.
There is some confusion over the media-shy Lim's age. His autobiography and newspapers give his birth date as 1918, but he publicly celebrated his 90th birthday at a party in April. In some Asian cultures, newborns start life with the age of one, not zero as in the West.
He found work as a building contractor and in the 1960s came up with the idea to develop a hilltop resort in mountain jungles near Kuala Lumpur. Genting Highlands became a major casino resort and fuelled the group's growth into other areas such as plantations, property, power generation and oil and gas.
Genting has recently expanded beyond mainly Muslim Malaysia, winning the Singapore casino contract last December and taking over British casino operator Stanley Leisure. It also has an interest in cruise line Star Cruises Ltd
The group's other listed companies are Asiatic Development, Resort World and Genting International