The 20-year-old pop star surprised a small crowd at Banger's Sausage House & Beer Garden in Austin, Texas, on Sunday night.
Bieber performed two songs, dedicating "Boyfriend" to ex-girlfriend Selena Gomez, who was backstage."This goes out to my baby girl," Bieber told a crowd of about 100 people.
The bar was hosting an event for Bieber's manager, Scooter Braun. Surprise performers included Bieber and boy band The Wanted. Cody Simpson, Dan + Shay, Tori Kelly and Rixton, who are among Braun's clients, also performed.