The "Courage World Tour" began in 2019, and Dion had completed 52 shows before the Covid-19 pandemic put the remainder on hold.
She later cancelled the North American section of the tour due to her health problems.
It was to be the Grammy winner's first global concert tour in a decade and the first without her husband-manager Rene Angelil, who died from cancer in 2016.
The showbiz community voiced support for Dion on Instagram, with fellow singer Gwen Stefani, fashion designer Donatella Versace and actress Kate Hudson among tens of thousands leaving well wishes.