Demi Lovato
The singer performs at the 2015 Y100 Jingle Ball at BB&T Center in Sunrise, Florida.
Selena Gomez
The singer opts for a sexy black look at the iHeartRadio Z100 Jingle Ball in NYC.
Selena Gomez
The singer sports another sexy black look onstage.
Selena Gomez
The singer was gorgeous in white when she walked the red carpet.
Hailee Steinfeld
The actress and new pop singer sparkles in crimson.
Joe Jonas
Someone's not Team Pepsi...
Demi Lovato
The singer gives off a rock star vibe.
Fifth Harmony
Hello ladies!
Chloe Grace Moretz
The actress sparkles at the iHeartRadio Z100 Jingle Ball in NYC.
Shay Mitchell
The actress went for gothic glamour in a lace Oglia-Loro dress.
Ariel Winter
The Modern Family star appears at the iHeartRadio Z100 Jingle Ball in NYC.
Ariel Winter
Work it!
Selena Gomez
The "Same Old Love" singer strikes a sultry pose.
One Direction
Niall Horan, Harry Styles, Louis Tomlinson and Liam Payne strike sexy poses backstage.
Selena Gomez
The singer performs at 102.7 KIIS FM's Jingle Ball 2015, presented by Capital One, at Staples Center in Los Angeles.
Chloe Grace Moretz, Maika Monroe & Alex Roe
Three's company!
Chris Harrison
Before showtime, The Bachelor and Bachelorette host enjoys some tasty Girl Scout cookies.
Zedd
Before his performance on the Jingle Ball stage, the world-famous DJ rocks out to Guitar Hero Live.
Kyle Richards & Kenya Moore
When Real Housewives collide! The Bravo stars meet up at 102.7 KIISFM's Jingle Ball gifting suite.
Harry Styles & Niall Horan
The One Direction singers gives us a smile!
Hailee Steinfeld
The actress-turned-singer performs at L.A.'s Jingle Ball.
Harry Styles
The One Direction star and his hair perform at L.A.'s Jingle Ball.
Robert Herjavec & Kym Johnson
Cute couple alert! The Hollywood pair enjoys a little shopping before enjoying One Direction, Selena Gomez and more artists perform.
Ellie Goulding & Becca Tilley
"So FREAKING AWESOME meeting the beautiful @elliegoulding in the Mercedes Benz meet and greet room tonight!" the former Bachelor star wrote on Instagram. "Thank you for being so sweet!"