Bieber, 20, was in Miami working with 15-year-old singer Madison Beer when Gomez made a surprise visit at the Hot Factory recording studio, reported E!Online.
Madison's mother Tracie Beer posted pictures on Instagram showing Gomez and Bieber in the same place at the same time.
The 'Baby' hitmaker also posted a picture of Madison and Gomez, 21, with the caption, "And now this beauty comes to visit.