Instagram Domination: Her 77.8 million followers make Gomez the single most popular person on Instagram (sorry, Taylor).
SNL Host: She made a memorable appearance as a musical guest in January, performing "Hands to Myself" on a bed, but has never hosted the show.
No. 1 Album: Gomez has sent both of her studio albums to No. 1 on the Billboard 200: Stars Dance in 2013 and Revival in 2015.
Billboard Cover: Ariana Grande on Defending Female Pop Stars and Staying Away From Drama
Child Stardom: Grande played Cat Valentine on Nickelodeon's Victorious and the spinoff show Cat & Sam. In 2015 she guest-starred on Fox's Scream Queens.
Instagram Domination: With 71.7 million followers, Grande is not far behind Gomez and consistently among the service's most popular users.
SNL Host: Grande, who also performed in 2014, hosted in March, nailing impressions of other stars and contributing to "This Is Not a Feminist Song."
No. 1 Album: Like Gomez, Grande has released two albums, and both have gone to No. 1. The question now is whether Dangerous Woman will too.
Ariana Grande: The Billboard Cover Shoot
Child Stardom: Another Barney & Friends alum, Lovato appeared in two other Disney shows and, most recently, the fifth season of Glee.
Instagram Domination: 38.7 million followers ain't bad, but Lovato missed Instagram's ranking of 2015's top 10 pop stars.
SNL Host: Lovato was a musical guest in 2015, on an episode in which she also joined host Tracy Morgan in his "Astronaut Jones" sketch.
No. 1 Album: Of the five albums she has released since 2008, Lovato has managed to lodge one of them in the No. 1 spot: 2009's Here We Go Again.
This article was originally featured in the May 28 issue of Billboard.