Ozzy Osbourne has announced that this is it. He's going on a long World Tour starting in 2018, and it will extend into 2020. Then, he may do a few gigs, but he's pretty much retiring from touring.
This comes nine months after Black Sabbath decided to never tour again.
"People keep asking me when I’m retiring," Osbourne said in a statement. "This will be my final world tour, but I can’t say I won’t do some shows here and there."