The Baby hitmaker dropped by Whitney Elementary School ahead of his performance at Sunday's (19May13) Billboard Music Awards and spent time distributing food donations to kids as they cried tears of joy at meeting their idol.
Bieber's trip was documented by cameras at U.S. breakfast show Today and in one clip, the 19 year old is featured comforting a star-struck girl, saying, "Don't cry, how are you? Give me a hug."
The singer also sat down with headmistress Sherrie Gahn, who has made it her mission to provide needy students and their families with food and clothes throughout the year, promising to stock the school's pantry with endless treats for the next 12 months as part of his work with the charity organisation.
A grateful Gahn said, "Justin Bieber coming means a lot, these kids get to see that someone really important to them believes in them."
The pop star had a great time too - in a post on Twitter.com he wrote, "Thanks to Whitney Elementary and Sherrie for letting me come by again. Love u guys. U inspire me."
It's not the first time Bieber has made a visit to the school - he staged a holiday concert for the students in 2011 and also made a $100,000 (GBP62,500) donation to help with Gahn's fundraising efforts.
Bieber was in Las Vegas for the Billboard Music Awards, which took place at the MGM Grand Garden Arena on Sunday night (19May13).