(In 2018, the Billboard staff released a list project of its choices for the Greatest Pop Star of every year, going back to ...

Taylor Swift is Billboard's Greatest Pop Star of 2015 for how the former country hitmaker fulfilled her globe-conquering pop superstar dynasty.

Justin Bieber is Billboard's Greatest Pop Star of 2016 for how he returned from a low point to scrape some of the 2010s' greatest pop heights.