Celine Dion (File Photo: AFP)
The 55-year-old Canadian revealed last year that her condition -- Stiff-Person Syndrome -- was affecting her singing.
"I'm so sorry to disappoint all of you once again... and even though it breaks my heart, it's best that we cancel everything until I'm really ready to be back on stage," the "My Heart Will Go On" singer tweeted.
"I'm not giving up... and I can't wait to see you again!" she added.
A statement released by her tour said: "With a sense of tremendous disappointment, Celine Dion's Courage World Tour today announced the cancellation of all remaining dates currently on sale for 2023 and 2024."
"I'm working really hard to build back my strength, but touring can be very difficult even when you're 100 percent," Dion said in her statement, which was also posted on Instagram.
Dion, one of the top women singers with an octave-busting voice, is the author of hits like "Because You Loved Me", "My Heart Will Go On" and "Think Twice".
In December 2022, she posted a tearful video on Instagram to say she had recently been diagnosed with Stiff-Person Syndrome and would not be ready to start her European tour in February as planned.
She said the disorder was causing muscle spasms and was "not allowing me to use my vocal cords to sing the way I'm used to".
Sufferers commonly experience stiff muscles in the torso, arms and legs, with noise or emotional distress known to trigger spasms.
The cancellations will affect her 16-country tour in Europe which was due to start in Amsterdam in August and conclude with two dates at the O2 arena in London in April next year.
Tickets purchased for the cancelled dates will be refunded via their original point of sale, her website said.
Her "Courage World Tour" began in 2019, and Dion 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.
The dates in Europe were to have been the Grammy-winning singer's first global concert tour in a decade and the first without her husband-manager Rene Angelil, who died from cancer in 2016.
Fans online reacted with disappointment, but wished Dion well.
"Not surprising, but no less sad. Courage to you Celine, we are with you," wrote fan information account @LesRedHeads.
"You don't have to apologize queen! Take care of yourself. Your health should take number one priority," wrote @notaerz.
Dion had sparked hopes of a recovery when she released a new album "Love Again" last month, the soundtrack for a film of the same name, which contained five new songs as well as past hits.
The youngest of 14 children, Dion was born in Quebec, Canada and got her start at 12, when her mother sent a recording of her to Angelil, who mortgaged his own home to finance her first album.
She began singing in French, but started bellowing out hits in English after taking English lessons in the 1980s.
She gained worldwide fame in 1997 with "My Heart Will Go On", the theme to James Cameron's epic film "Titanic".
She parlayed that success into a regular gig at Caesar's Palace in Las Vegas, playing for audiences night after night for 16 years, with only a few breaks.