Ozzy Osbourne said that following extensive spinal surgery he is not "physically capable" of doing his tour dates in Europe in May and June.
The 74-year-old former Black Sabbath singer had a fall at home in 2019 which aggravated injuries from a near-fatal quad bike crash in 2003.
Since that time, Osbourne has performed during the closing ceremony at the Birmingham 2022 Commonwealth Games and an NFL game in the US in September.
He told his fans on Instagram on Wednesday: "This is probably one of the hardest things I've ever had to share with my loyal fans. As you may all know, four years ago this month I had a major accident, where I damaged my spine. My one and only purpose during this time has been to get back on stage."
Osbourne said his singing voice is "fine" but that, following three operations, stem cell treatments, physical therapy sessions, and Cybernics (HAL) Treatment, his body is "still weak."
He added: "I am honestly humbled by the way you've all patiently held on to your tickets for all this time, but in all good conscience I have now come to the realisation that I'm not physically capable of doing my upcoming European/UK tour dates, as I know I couldn't deal with the travel required."
Osbourne went on: "Never would I have imagined that my touring days would have ended this way. My team is currently coming up with ideas for where I will be able to perform without having to travel from city to city and country to country."
He also thanked fans, crew, family and the band Judas Priest "for their endless dedication, loyalty, and support."
Osbourne, whose real name is John Osbourne, was known throughout his heavy metal career as the "Prince of Darkness."
He was lead vocalist of heavy metal band Black Sabbath, which he formed in 1969 alongside guitarist Tony Iommi, bassist Geezer Butler and drummer Bill Ward.
The singer-songwriter also starred in fly-on-the-wall TV show The Osbournes, which documented the family's life in Los Angeles.
Last year, Osbourne said he and his 70-year-old wife, Sharon, who is a former judge of America's Got Talent and The X Factor, would be moving from the US to their property in England.
The couple met when Sharon was 18 and they married on July 4, 1982 in Hawaii.
They have three children together – Aimee, Jack and singer Kelly, who duet with her father on the UK number one single Changes in 2003.
Osbourne's last album, Patient Number 9, was released in September and reached number two in the UK charts. – dpa