But before she takes the stage, the pop star hit the red carpet wearing a fierce cheetah-print dress.
The show is shaping up to be an eventful night in the music business, in no small part because of the laundry list of performances that are booked. Along with the Lovato/Aguilera tandem, fans will get to see Janet Jackson perform on television for the first time in nine years and Shawn Mendes and Khalid give a performance with the choir from Marjory Stoneman Douglas High School.
Other performances include Kelly Clarkson (who will also host), Salt-N-Pepa, Dua Lipa, Jennifer Lopez, John Legend, Macklemore with Kesha, Ariana Grande, Zedd with Maren Morris and Grey, the Korean pop band BTS and Camila Cabell with Pharrell.
Presenters for the show include Hailey Baldwin, Tyra Banks, Alison Brie, The Chainsmokers, Ciara, Andy Cohen, Simon Cowell, Darren Criss, Halsey, T.I., Nick Jonas, Mila Kunis, Ne-Yo, Rebel Wilson, Ashlee Simpson and Jenna Dewan.
Lovato has been incredibly open with fans about her personal life an emotional well-being in recent months. Back in March she gave an interview with In Style and described her sexuality as "very fluid"
"I'm very fluid," she said. "I think love is love. You can find it in any gender. I like the freedom of being able to flirt with whoever I want."
"I am on the dating app with both guys and girls," she continued. "I am open to human connection, so whether that's through a male or a female, it doesn't matter to me."
Lovato was previously in a six-year relationship with That 70s Show actor Wilmer Valderrama that ended in 2016.
"I'm not suffering because I'm alone," Lovato said. "There were many years I was in a relationship and I wasn't learning about myself. Now I'm learning about what I like, what I need, and what I want."
She revealed in her biographical documentarySimply Complicated that she purposefully ended the relationship with Valderrama to "explore" her life as a single woman.0comments
"The sparks never faded, but there are issues that I haven't conquered yet that I know I won't conquer if I'm relying on somebody else to take care of the loneliness," she said. "I just wasn't ready and there was so much in my life that I hadn't explored yet. That was one of the reasons why we broke up because I've never been alone. ... It had nothing to do with falling out of love, we decided together we just probably are better as friends."
Photo: Getty Images: Jeff Kravitz/FilmMagic