The retired Queensland rider had a new career as a racing steward and worked on the panel at the Gold Coast races on Saturday, just hours before his death.
News of the death of Palmer, a whiz apprentice who rode successfully in Hong Kong and Macau, particularly rocked Queensland racing where he had been a steward for the past three years.
Racing Queensland's chief steward Alan Reardon said he had been shocked to receive the news.
"I have known Gary for 40 years. He was a champion jockey and had been an integral part of the stewards panel since he joined us," Reardon said.
Palmer was an outstanding apprentice jockey riding close to 400 winners as a junior.
He enjoyed a strong partnership with legendary trainer Tommy Hughes.
He was 16 when he won his first Group 1 race on Grey Affair in the 1977 Doomben Cup.
Palmer outrode his allowance and was transferred to Tommy Hughes in Melbourne where he tasted Group 1 success on Salamander in the 1978 Toorak Handicap.
He returned to Brisbane in the early 1980s and continued to ride winners including Daybreak Lover in the 1986 Stradbroke Handicap.
Palmer had stints in Macau and Hong Kong before returning to Brisbane and winning another Stradbroke in 1995 on Rouslan.
After retiring in the late 1990s he dabbled in business ventures before joining the stewards panel in January 2012.
Racing Victoria chairman of stewards Terry Bailey described the news as "devastating".
Bailey said Palmer was someone to be admired not only as a first class jockey, but more importantly as a person.
"He was a great rider, but a greater person," Bailey said.
Greg Hall, who grew up with Palmer, was shocked at the news. "Gary was a pretty quiet sort of guy, but when you got to know him , you soon realised what a champion bloke he was," Hall said.
Racing Queensland CEO Darren Condon said Mr Palmer was a much-loved member of the Queensland racing fraternity and the thoughts of the industry were with his family.
“Gary grew up in a racing family- his father Ron was a trainer-jockey and his two sons Matthew and Michael went to become jockeys themselves. His success both at home in Queensland and overseas, show just what a true champion he was,” Condon said.
“Gary was also a very well-respected member of our stewards’ panel and it was fitting that he should continue his involvement in the industry in an officiating capacity when he stopped riding.
“The thoughts and prayers of Racing Queensland and the wider community are with Gary’s family at this time and I would please ask that their privacy be respected.”
Palmer's sons Matthew and Michael were both talented apprentice jockeys.
He is survived by his wife Debbie and two sons.
Gary Palmer's biggest wins: Stradbroke Handicap (Daybreak Lover 1986, Rouslan 1995), Toorak Handicap (Salamander 1978), Brisbane Cup (Love Bandit), Doomben Cup (Grey Affair 1977), Chipping Norton Stakes (Grey Affair 1978), QTC Oaks (Look Aloft 1984), QTC Derby (Florissa 1977).