Justin Bieber Dating Hailee Steinfeld

12:20 PM PT -- A rep for Hailee says she and Justin are friends. That's her side of it.

Our sources are clear ... their relationship has left the friend zone.

Justin Bieber's moved on to a new Hailey -- different spelling though because he's now dating singer and actress Hailee Steinfeld ... TMZ has learned.

It's all still fresh. Our sources tell us they've only been seeing each other for a little over a month -- though that's a lot in Bieber's world. We're told they were introduced by pastor Carl Lentz. They both attend his church.

Last month, JB dropped a giant clue things were heating up between them when he was photographed mid-FaceTime with the "Pitch Perfect 2" star.

Justin's in NYC now and we're told they met up after Hailee went to the Met Gala ... solo.