South African Pistorius was found guilty of culpable homicide earlier this month after he shot and killed girlfriend Reeva Steenkamp in his home in February last year.
The eight-time Paralympic medalist will learn his fate next month and faces a maximum prison sentence of 15 years.
In the immediate aftermath of the verdict from Judge Thokozile Masipa, Craig Spence, the IPC's director of media and communications, stated that the organisation will not prevent Pistorius from competing, if the athlete chose to do so once any potential sentence has been served.
Weir, who has won two silver and two bronze medals to go with his six golds in wheelchair racing, believes any return for Pistorius will be detrimental.
"I think it would be a circus if Pistorius came back," the Brit told the Daily Telegraph.
"The IPC should take a stand and rule him out of competing. The Paralympic Movement should not be about one person, and that's the danger here."
IPC president Philip Craven, meanwhile, moved to clarify the governing body's position.
"Is there a possibility that legally Oscar Pistorius could come back and compete at the Paralympic Games? Yes, of course, there is a legal possibility of that," he said.
"Whether it will happen or not, is highly hypothetical. We don't even know the sentence yet.
"There will be a lot of water to pass under the bridge before we are even near to that stage, and what was widely quoted in the media last week was taken out of context."