Justin Bieber has stunned fans at an elementary school in Las Vegas by announcing plans to perform a Christmas concert there in December (11).

The pop star was so moved by Whitney Elementary School principal Sherrie Gahn's story on a recent episode of The Ellen DeGeneres Show he decided to give her and her students a festive boost.

Over 70 per cent of the kids at Whitney don't have permanent homes, and Gahn has made it her mission to give the students a better life.

DeGeneres surprised the school with a $100,000 cheque, and now Bieber will perform festive tunes from his new Under The Mistletoe album.