Bieber, 20, wore a black jacket over a long tee, a pair of washed out blue jeans and black boots. He looked nervous as Campbell, 44, who donned a black tee that read 'Fashion Against Ebola', put her arm around his shoulder while posing for a picture.
The fashion show was held to raise money for the Ebola crisis.
Some Hollywood stars like Paris Hilton, Michelle Rodriguez, Tyson Beckford, Kelly Osbourne, Brad Goreski and NeNe Leakes showed their support by walking the runway.