Baldwin, 18, was rumoured to have started dating the 'Baby' hitmaker after his split from Selena Gomez, reported Daily Mirror.
"I've known him since I was so young - since I was like 13 - and we've just been good friends over the years. We have just stayed close and there's nothing more to it than that," she said.
Baldwin, who celebrated her birthday a few weeks ago, was reportedly "treated like a princess" by Bieber on her special day.