Jones' Saturday performance in Monte Carlo was scheduled at the end of his three-month"Praise & Blame" tour.
"Sir Tom was ordered by doctors not to perform in Monte Carlo yesterday evening, due to severe dehydration," said a statement posted on his website
"This was extremely disappointing for Tom, the band and all connected with the tour. This was the last date of a very successful 3 month tour, where many of the shows were in locations that were in the throes of high summer heat. There are NO heart problems, as has been reported in the press."
It added that Jones wanted to relay his regrets for causing disappointment and inconvenience to fans who had planned to attend his show and hoped to return to the city again soon.
The Daily Mail
had reported that on Saturday theatrical producer David King tweeted: "Tonightâ€™s concert at the Sporting Club, Monte Carlo, cancelled as Tom Jones admitted to hospital with a heart scare."
The Associated Press
reported that the Princess Grace Hospital said the 71-year-old Welsh singer was doing well on Sunday, but there was no information on when he would be released.
Jones had lost weight earlier this year, after cutting out alcohol and changing his diet.
He talked to the BBC
in June about his busy summer schedule.
Many people have posted get well messages on Jones' Facebook