There were reports that Stewart, 23, had struck up a close relationship with Pitt after meeting the Boardwalk Empire star during Paris Fashion Week in France, but his spokesperson has moved swiftly to dismiss the claims, reported Sun online.
"While we do not comment on our clients' personal lives, please know that there is absolutely no truth whatsoever to this rumour that Michael Pitt and Kirsten Stewart are dating," Pitt's representative said in a statement.
Pitt, 32, has previously romanced model Jamie Bochert.