It started when Mill sent a Twitter salvo aimed at Drake on Tuesday night after the VMA nominations were announced.
"Stop comparing drake to me .... He don't write his own raps! That's why he ain't tweet my album because we found out!," Mill tweeted.
Drake has yet to respond, but his supporters took to Twitter. A tweet from Kelly's acccount was particularly indignant.
"You're no longer welcome in Toronto, @MeekMill," read the missive. Kelly, 73, was once the city's deputy mayor.
Mill wasn't about to let that response go unchallenged.
"Aye white man @norm what gives you the audacity to tell me I can't come somewhere over me voicing my opinion! U sound like a thug lol," he fired back.
Kelly returned the volley, and backed down on his suggestion that Mill stay away.
"Aye American @MeekMill. Didn't say don't come. Just puzzled why you'd diss a Canadian hero a week before coming to his city."
Mill has a concert scheduled in Toronto on Tuesday.