Osbourne, 70, will remain under doctor's care in L.A as he "recovers from an injury sustained while dealing with pneumonia."
The illness forced the metal legend to axe large parts of his No More Tours 2 tour earlier this year.
The remaining US dates will be now be re-arranged for 2020.
It's the latest in a serious of health issues for the rocker, who - according to his wife Sharon - stopped breathing and his heart stopped beating after a quad bike accident in 2003.
In a statement on Facebook, Osbourne said: "I can't believe I have to reschedule more tour dates.
"Words cannot express how frustrated, angry and depressed I am not to be able to tour right now."
He added: "I'm grateful for the love and support I'm getting from my family, my band, friends and fans, it's really what's keeping me going.
"Just know that I am getting better every day… I will fully recover… I will finish my tour…I will be back!"
The former Black Sabbath frontman has no scheduled UK dates this year, but was due to resume his rock 'n' roll duties next month at the Rocklahoma festival in Oklahoma,
His last gig was a set at his own Ozzfest in California on New Year's Eve 2018.